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ATI Radeon HD 5970: The Undisputed Performance Champ

Loyd Case & Gordon Mah Ung — Wed, 18 Nov 2009 11:00:00 -0600

AMD’s Radeon HD 5970 takes the performance crown, and now offers DirectX 11 GPUs top to bottom.

You can forgive AMD for stealing a line from Nvidia’s playbook. From the name and marketing materials, it’s not obvious that this card is a dual GPU card. One AMD chart even refers to the card as the “ATI Radeon HD 5970 GPU,” much like Nvidia’s 295 GTX is a dual GPU card that’s sold as if it were a normal graphics card.

Let’s take a quick look at the speeds and feeds of the new card, and then discuss additional features. We’ll compare them to the Radeon HD 5870 single GPU card; there are differences in core and memory clock speeds.

ATI Radeon GPUs Compared

Model	HD 4870	HD 5970
GPU	Single HD 5870 GPU	Dual HD 5870 GPUs
Stream Processors	1600	3200
Core Clock	850MHz	725MHz
Memory	1GB 1200MHz GDDR5	2GB 1000MHz GDDR5
Texture Units	80	160
ROPs	32	64
Memory Data Rate	4.8Gbps	4.0Gbps
Compute Performance	2.72TFLOPs	4.64TFLOPs
Idle Power	27W	42W
Max Power	188W	294W

Most features simply double, since there are two identical GPUs with the same memory per GPU. However, note the memory bandwidth is lower, since the memory clock is lower. Also, overall compute performance isn’t quite double, since the engine clock for each GPU defaults to 725MHz, rather than the single GPU 5870’s 850MHz.

In addition to the paired GPUs, the card maximizes performance with a new second generation PLX PCI Express 2.1 bridge chip. This speeds up communications between the two GPUs.

The older Radeon HD 4870 X2, AMD’s last dual GPU card, often suffered from serious overheating problems, so AIT has taken steps to improve overall thermal efficiency. The first step is to used specially screened GPU chips with the minimum amount of leakage current. The thermal system consists of a vapor chamber, with heat dissipation via a fully vented exhaust system. Finally, a multipoint, programmable PWM fan controller ensures fan speeds consistent with overall thermal output. The whole affair is rated to dissipate 400W, or over 100W of headroom.

The use of low leakage GPUs suggests that the core clock speeds could be pushed higher than the default 725MHz. Given that the card can dissipate 400W of overall thermal output, ATI has decided to leave the card unlocked, letting users overclock it to their heart’s content. The company is even making available an overvoltage tool, and suggests that the card has enough headroom to push the engine clock to above the 850MHz of the single GPU HD 5870 and the memory speeds up to the 1200MHz of the 5870. In The HD 5970 also sports sophisticated digital voltage regulators, real time power monitoring and Japanese pure ceramic capacitors, which facilitate higher clock speeds. (The reason for the more conservative default clock speeds is that the company needs to make allowances for the thermal environment inside PC cases, which may be less optimal.)

What about power efficiency? The HD 5970 offers the same clock gating capability as the single GPU variant. In addition, the card offers an ultra low power state that puts one GPU to sleep, which cuts the overall power draw of that GPU by half the normal idle performance. The card idles at 42W, only 15W higher than the 27W of the HD 5870. Of course, the card sucks 294W at full throttle – and that’s at the default clock speeds. So you’ll need a power supply with the later PCI Express 8-pin power connector – the HD 5970 uses one eight pin and one six pin connector from the PSU.

The onboard connectors are slightly different from the original HD 5870: two DVI-I connectors and one mini-DisplayPort attachment, first popularized with Apple’s MacBook Pro laptops and iMacs. All three can be attached simultaneously, and drive three displays at the same time. Note that most DisplayPort enabled monitors which aren’t Apple displays ship with standard sized DisplayPort cables, so you’ll need to obtain a mini-DisplayPort to standard DisplayPort cable if you want to take advantage of that connection option.

Performance

We tested three graphics cards: the Radeon HD 5970, the Radeon HD 4870 X2 and the GeForce 295 GTX. Note that the 295 GTX only ships with 1792MB of GDDR3 memory (896MB per GPU). The Nvidia GPUs on the 295 GTX have a full complement of 240 shaders, like the 285GTX, but only a 448 bit wide memory bus, similar to the GeForce GTX 260 line of graphics chips.

All games were run at two settings: 1920x1200, 4xAA and 2560x1600 4xAA. All detail settings on all games were maxed out. We also report the results from 3DMark Vantage’sdefault, performance setting and the extreme setting. In addition, we’re tossing in the results from the eVGA GeForce 285 GTX SSC and XFX Radeon HD 5870 at the 1920x1200 resolutions, so you can get an idea as to how much you gain from the dual GPU cards.

We used our standard graphics test system for benchmarking graphics cards:

Test System

Component	Model
CPU	Intel Core i7 975 @ 3.33GHz
Motherboard	Asus Rampage II ExtremeX58
Memory	6GB Corsair Dominator DDR3-1600 @ 1333MHz
Hard Drive	Seagate 7200.12 1TB
PSU	Corsair 850W
Operating System	Windows 7

The HD 5890 seems much better behaved than its predecessor, the HD 4870 X2. Although the HD 5970 fan noise became quite audible at high loads, it seemed much quieter than the 4870 X2. More telling was our experience removing the cards immediately after completed benchmarking runs. The 4870 X2 was extremely hot to the touch – we had to handle it carefully to avoid burnt fingers – while the 5970 was cooler to handle (though still very warm.) Much of this was no doubt due to the vapor chamber covering the back side of the card.

As we expected from our previous experience with the Radeon HD 5870, the dual GPU HD 5970 pretty much smokes the competition. At its targeted $599 price point, the performance needs to be stellar – and it is. Let’s check out the performance charts.

1920X1200 4XAA

Model	eVGA 285 GTX SSC	Radeon HD 4870 x2	GeForce GTX 295	XFX 5870	Radeon HD 5970
3DMark Vantage (Perf)	13941	14458	19342	17089	21089
3DMark Vantage (Extreme)	6276	6574	9241	8312	12084
HAWX	62	78	93	68	104
Far Cry 2 (Action)	47	67	62	62	75
Far Cry 2 (Ranch Long)	56	77	73	74	116
BattleForge (DX10)	46	36	33	47	61
Crysis (DX10)	22	33	29	32	44
Resident Evil 5	87	126	115	100	135
X3: Terran Conflict	93	101	100	101	107
STALKER: Clear Skies	27	38	40	36	53

2560x1600 4XAA

Model	Radeon HD 4870 X2	GeForce GTX 295	Radeon HD 5970
HAWX	53	54	76
Far Cry 2 (Action)	18	59	65
Far Cry 2 (Ranch Long)	50	55	82
BattleForge (DX10)	23	20	39
Crysis (DX10)	19	18	24
Resident Evil 5	88	85	102
X3: Terran Conflict	90	59	101
STALKER: Clear Skies	22	20	31

There’s no question the Radeon HD 5970 is the fastest single desktop graphics card you can buy today. The real question is if it’s worth $200 more than a single Radeon HD 5870. Certainly if you’re running a 1920x1200 display, we’d recommend the single GPU card. But if you’re running triple displays, or a 30-inch, 2560x1600 monitor, and you want to push polygons at full resolution, you should consider the Radeon HD 5970. But make sure you’re willing to pay the cost.

Another note: this card is enormous. It’s an actual foot-long graphics card; make sure you’ve got a case deep enough to handle it.

Then there’s the whole issue of CrossFire. The HD 5970 is essentially a pair of downclocked HD 5870s in CrossFire mode. When the game can take advantage of CrossFire – as it does in our benchmarks – you can see huge performance gains. If the game can’t make use of CrossFire, then you own a pricey single GPU card that doesn’t run as fast as the HD 5870.

But what about running TWO of these cards in CrossFire mode? Find out on the next page.

Dual-5970 CrossFire Performance

We were fortunate enough to get not one, but two 5970 cards to test in our lab. The two cards came in Falcon Northwest's brand new Talon PC, which is the first 5970-equipped system we've reviewed.

You can read our full review of the kick-ass Falcon Northwest Talon here, but the system specs are below for your reference. Note that the Talon is a Lynnfield-based Core-i7 system, overclocked to 3.93GHz, as opposed to the 3.33GHz Core i7-975 Bloomfield proc we used in our testbed to benchmark the lone 5970 card.

Specifications

Processor	Intel 2.93GHz Core i7-870 @3.83GHz
MOBO	MSI P55-GD65
RAM	8GB Crucial DDR3/1600
Videocard	Two MSI Radeon HD 5970 in CrossFire mode
Soundcard	Onboard
Storage	Two Intel X25-M 80GB in RAID 0; 1TB Samsung Spinpoint 7,20rpm hard drive
Optical	Lite-On 22x DVD burner
Case/PSU	Silverstone case with Exotix paint job and 1,000 Silverstone PSU

In addition to a 48-hour plus burn-in period, we wanted to push Falcon Northwest’s dual-Radeon HD 5970 cards on something a bit harder so we connected the FNW Talon to a 30-inch 2560x1600 panel and cranked several benchmarks to maximum. The result? Impressive. Although, the drivers we used were still fairly early, the performance of the card is unquestionable. We had some concerns of running the card in a dual x8 mode (a limitation of the P55 chipset and Lynnfield platform) instead of full x16’s that an X58 platform would give us but the results don’t seem to show too much to be concerned about. The cards seem to offer better than expected scaling, even with early drivers.

Dual-5970s on Falcon Northwest's Talon PC

	HD 5970 Crossfire On	HD 5970 Crossfire Off
3DMark Extreme Overall (1900x1200)	18954	11686
3DMark Extreme GPU (1900x1200)	18763	11384
3DMark Extreme CPU (1900x1200)	23498	23561
3DMark Extreme GPU (2560x1600)	13494	9076
3DMark Extreme CPU (2560x1600)	23387	23399
Crysis, Very High, (2560x1600)	34.4 FPS	27.1 FPS
Far Cry 2 Ultra High (2560x1600)	185.2 FPS	107.4 FPS

Crysis, 1900x1200 (NO AA)	66.3 FPS	(did not run)
Crysis, 1900x1200 (16X AA)	64.3 FPS	(did not run)

Note that in Crysis, enabling 16X Anti-Aliasing doesn't seem to affect the framerate with CrossFire enabled.

Finally, a note on overclocking. The AMD overvolting tool has two settings for core and memory. You can overvolt the GPUs, overvolt the memory or both. Using the tool, we pumped up both voltage settings, then found the card to be stable at 870MHz core and 1250MHz memory (17 and 25% respectively.) Curiously, though, we saw little actual performance gain. 3DMark Vantage (extreme setting) only saw a 1% increase, from 12084 to 12182. We got two additional FPS in Crysis and either no increase or slight decreases in frame rate for Far Cry 2 and STALKER: Clear Skies. We probably need to do a better job of balancing memory and core clocks, but our initial experiences suggest that overclocking may not be worth the effort.

JPR is Likely Wrong about a Third of PCs Running Multi-GPUs in 2012

Paul Lilly — Tue, 18 Aug 2009 09:44:18 -0500

Three years from now, two-thirds of all new desktop systems will be mutli-GPU capable and of those, 30 percent will be rocking multiple graphics chips. Or at least that's the not-too-distant future Jon Peddie Research Group (JPR) laid out last week in a report on the history, technology, and future of multi-GPU computing. But are we really on the verge of widespread multi-GPU computing?

Not so fast, says Arstechnica. The JPR report points to the desire for high performance computing as the driving force for multi-GPU setups, noting high performance workloads are highly parallel and unsuited for CPU applications. But according to Arstechnica, JPR hasn't thought through the manufacturing angle.

"GPUs are composed of many parallel processing units, so any multi-GPU system involves simply ganging together still more of such small, simple processor cores," Arstechnica writes. "Because the cores are small and the workload is parallel, there is no limit on core count analogous to the limit on the number of processors that can profitably be used in a single x86 CPU. The limits on single-die GPU horsepower are manufacturing limits."

But it's not just about manufacturing. As Ars points out, only two percent of all desktop PCs sold last year came with multiple GPUs, and in Q4 of last year, only 15.2 million out of 38.5 million PCs sold came with even a single discrete graphics card. It's hard to imagine such a dramatic shift towards multiple GPUs in just three short years from now.

There's more to Ars' argument, which you can read here.

Image Credit: techreport.com

AVADirect Core 2 CrossFire DDR3 Gaming System

Gordon Mah Ung — Wed, 31 Dec 2008 11:15:00 -0600

Its official name is Core 2 CrossFire DDR3 Gaming System, but you can just call it the Quad Meister or Quaderino, if you’re into the brevity thing. What else could you possibly call a PC equipped with two ATI Radeon 4870 X2 cards (quad GPU cores), four Velociraptors (quad hard drives) and an overclocked Intel Core 2 Extreme QX9770 (uhh, quad cores)? Maybe we’re stretching here, but our nickname is certainly sexier than the PC’s official moniker.

This rig’s components are housed in an NZXT Khaos case with a custom laser-cut side. Optical storage is handled by a Samsung DVD burner and an LG Blu-ray burner. In magnetic storage, AVADirect hit us with a head scratcher. It equips the machine with four 150GB Velociraptor drives. Yeah, you read that right—WD makes a 150GB version of its spectacular Velociraptor drive. An Alphacool LCD display and a Corsair 1000HX PSU round out the package.

AVADirect stripes the four 150GB Velociraptor into one big RAID 0 array but doesn’t include a backup drive. Storing anything you care about on such an array is like trying to steal home—it’s a big risk for a big reward.

The last AVADirect machine we reviewed, the AVADirect Core 2 Duo SLI Gaming System (December 2007), was damaged during shipping and leaked coolant all over the place. This time, the company went with air cooling and, amazingly, was able to get the QX9770 overclocked to 4GHz using a heatsink fan the size of Jupiter. The good news is that it passed our stress test with flying colors. The bad news is that this machine also came damaged and had several screws stripped loose.

The Quaderino was roughly five percent slower than the Digital Storm Benchmark Crusher we reviewed last month (the Crusher’s water-cooled CPU was clocked about five percent faster). In gaming, the showdown was between the Crusher’s tri-SLI GTX 280s and the Quaderino’s Radeon HD 4870 X2 cards. In our UT3 test, the Quaderino was about 13 percent faster than the Crusher. In Crysis, however, the Radeons took a backseat to the GeForce cards. While the Digital Storm could belt out 54 fps in Crysis, the AVA Direct was down at 34 fps. Why? One theory is that since Crysis supports just three GPUs for gaming, the Radeons are at a disadvantage since each individual GPU core is slower than an individual GTX 280.
While Crysis is the more graphically intense game, we’re calling this fight a draw—especially since the Digital Storm system turns the price knob up to $9,000 while the AVADirect machine is $6,000.

The AVADirect box is a nice machine and sensibly priced, given the amount of hardware it packs. We question the storage configuration and are a bit concerned about getting two consecutive machines with shipping damage from the company. AVADirect needs to either look at its packaging or buy its shipping guy a cookie bouquet.

Still, the Quaderino is a fast box and represents well as the first PC we’ve received this year without a GeForce in it.

Dreaming of Massively Multiplayer Open Source

David Murphy — Fri, 19 Dec 2008 12:00:00 -0600

Remember Myst Online? You shouldn't. GameTap shut the servers for the fumbling MMO in the beginning of this year, leaving plenty of fans of massively multiplayer online puzzle-solving out in the cold. Until the rights were returned to Cyan Worlds, which promptly promised to resurrect the MMO under the clever acronym of MORE -- the Myst Online Resurrection Experiment. Which was all fine, until funding difficulties killed the project once again. Which has since been resurrected again (surpassing Jean Gray's record), this time as a result of Cyan Worlds turning the entire Myst Online platform over to the open source community.

Strangely, this is the first big announcement from any of the "larger" MMOs that involves open source in any fashion. When an MMO dies, it usually dies for good, regardless of how persistent the fan base is toward resurrecting the fallen title into a working project.

The curious part of Myst Online is that Cyan Worlds is going to host a server with all of Myst Online's data for its fans to use. It's quite a conciliatory gesture, especially since other dead MMOs that live on through fans and private servers usually end up having to extract engineer the materials themselves. As Ars notes, this is a great way to keep the game from dropping off the radar for good. The code release will invariably lead to a bunch of rogue servers, but even in this, Myst Online could find a larger base -- imagine a version of the game that's been customized to a completely different experience entirely? Don't discount the coding tenacity of rabid fans. Cyan Worlds certainly isn't.

We mentioned this being the only MMO that's gone the open source route. We can't think of any officially released MMOs that' have dumped their code to the community like this, but that's not to say that the gaming world is devoid of open-source MMOs:

Shown above, PlaneShift is a larger title that's attempting to push an art direction comparable to a modern-day retail MMO. The game features GM events, trading and crafting, and a separate "death realm" that you have to escape each time your character meets the reaper. All that, and it's an open-source title! This game is ready-for-download, unlike plenty of other open-source MMOs that exist more in idea than reality.

Crossfire isn't an MMO in the modern sense of the word, but it harkens back to the MUD era with its simple graphics and archetypal role-playing gameplay. The fact that it's still around in development since its creation in 1992 shows the strength of the open-source community to cling to projects. If people are still tweaking and adjusting a game like this, the sky is practically the limit for a robust title like Myst Online.

Speaking of originators, WorldForge is one of the earliest open-source MMO engines to be released with full-fledged graphics. The giant framework was primarily designed to help developers create alternatives to Ultima Online (if that helps to give away its age), although scant alternatives have actually been created since the framework's launch. You can check the full list here, which can be accessed using one of two 3D clients found here (Ember or Sear). Still, bookmark WorldForge's homepage if you like watching the efforts of a giant community working hand-over-fist to incorporate new functionality into an evolving MMO concept.

AMD Set to Launch ATI HD 4600, Its Answer to NVDIA GeForce 9500 Series, September 10

Mark Edward Soper — Mon, 01 Sep 2008 21:00:30 -0500

Tom's Hardware reports that AMD is set to launch the new ATI HD 4600 series of video cards on September 10. The HD 4600 is designed to compete with the GeForce 9500 series of video cards, and is expected to replace the ATI HD 3800 series.

HD 4670 versus HD 4650

The HD 4600 series, like the GT 9500 GT, provides best performance when used with GDDR3 memory, but will also be available with DDR3 and DDR2 memory. Cards based on the RV730XT GPU will be known as the HD 4670 (available in 1GB and 512MB RAM versions), while cards based on the slower RV730 Pro GPU will be known as the HD 4650 (available with 512MB of RAM).

Both GPUs will offer PCI Express 2.0 support, DirectX 10.1 support, physics and dynamic geometry acceleration, 24x CFAA technology, 128-bit memory bandwidth, HDCP support for full-quality HD playback, and CrossFire support. The HD 4670 has a power requirement of only 70 to 80 watts, while the HD 4650 requires only 50 to 55 watts, making them ideal for home theater systems.

See Tom's Hardware for additional details and illustrations, and see GPU Café for pictures of an HD 4670-based card featuring ~~HDMI~~ DisplayPort (a hat tip to reader FOX72 for the correction) and DVI ports.

Illustration courtesy of GPU Café.

Disappearing Drives, Connectors, and Copy Protection Problems.

The Maximum PC Staff — Wed, 28 May 2008 13:26:15 -0500

Screwed-up USB Storage

I have a Maxtor 500GB OneTouch 4 external hard drive that isn’t loading properly to my desktop, which is running Windows XP Home Edition SP2, an AMD Athlon XP 1600+ with a VIA chipset, and more than 1GB of RAM.

My older Maxtor 3000LS 40GB drive works perfectly. I know the Maxtor OneTouch 4 is OK because it works with my Toshiba Satellite laptop with Windows XP.

When I plug the OneTouch 4 into my desktop, I get a yellow question mark in the Device Manager for Other Devices, which suggests that Windows recognizes the drive on some level. However, I still get a Code 28 message that says drivers for this device are not installed. What can I do (without reinstalling Windows, updates, or other programs) to load the proper drivers? Is there anything in the registry that might be added or deleted to make this work?

—Len Kane

The OneTouch 4 should just pop up and work as normal in Windows XP since the drivers for the external storage device are written on the device itself. You don’t have any discs or downloads to turn to.

The Doc suspects the drive itself is working just fine. After all, if it didn’t, you wouldn’t be able to pull it up on any machine, period. To find an answer to your dilemma, the Doctor hit up Seagate for assistance.

The company suggests that you reset Windows’s Infcache.1 file. To do this, launch Windows Explorer and type C:\windows\inf in the Explorer bar. Press Enter, which will pull up the inf folder. Search for the Infcache.1 file and delete it. Unplug your OneTouch 4 and restart your computer. When Windows boots again, the operating system will have rebuilt the Infcache.1 file. Seagate says this should fix the problem that’s causing Windows to issue a Code 28 message when you plug in the drive.

If it doesn’t, you have one alternative: Run a repair/restore installation of Windows XP since something is probably mucking up your USB drivers.

Sharing Data

Do CPU-intensive programs perform better on a drive that’s physically separate from the OS drive, especially if the drives do not share the same data cable? In other words, the OS is on a SATA drive and the hard-hitting program is on an IDE drive, for example. Where does the page file come into this? Should it be placed on a third drive?

—Timothy Joyce

If the application is truly 100-percent CPU-bound, you are unlikely to see an impact by moving the output to a second or third drive. For example, encoding a two-pass H.264 video is almost entirely processor driven and produces very small disk writes and reads. But if you are editing a large Adobe Photoshop file that is caching to the hard drive, having Photoshop write to a secondary or tertiary drive will actually help performance. In that scenario, your performance is gated by the CPU and somewhat by the drive you are writing to.

You can always try putting the Windows page file on a separate drive, but you’re probably better off adding more RAM—unless, of course, the original drive is a complete loser; then you might see a small performance boost, but nothing extraordinary.

CrossFire and nForce?

My latest rig has a Gigabyte GA-M59SLI-S5 motherboard, and I’m using an ATI Radeon 1950XTX. I had an Nvidia 7950 GX2 originally and was going to use it in an SLI configuration down the road. That card ended up being a real pain, so I exchanged it for the ATI. Can I add a second ATI card and run CrossFire since the cards would be sitting in an Nvidia-chipset mobo made for SLI? I’ve found conflicting info on the subject and don’t want to spend the money on a second card if it won’t work.

—Greg Bauman

HP’s Blackbird 002 machine is one rig that can run CrossFire AMD cards on an nForce-based motherboard, thanks to custom drivers.

There’s no good reason you can’t run two AMD videocards in CrossFire on an SLI motherboard, but there is a political reason—and as usual, politics trumps fairness. HP’s Blackbird PC allows two AMD cards to run in CrossFire mode on an SLI motherboard, but AMD has no plans to release the drivers that support this to the public. Still, AMD is making special drivers for Hewlett-Packard, Dell, and Alienware that will allow the companies to run CrossFireX cards on nForce SLI boards. AMD says it will only do so because those OEMs can ensure that the drivers work properly on nForce motherboards.

HDCP Woes

I built a PC about a year ago, and now I’d like to add a Blu-ray drive so I can watch movies on it. I think I am screwed by HDCP. Is there a workaround available that will let me watch HD movies without having to buy a new graphics card and monitor? I am using DVI connections, but I understand that this is not the same as HDCP, despite both products being advertised as HD-compatible. My videocard is a Gigabyte GeForce 7600 GS (256MB) and my monitor is an Acer AL2423W.

—Wade Tanev

Your Gigabyte card is indeed “HD compatible,” but that doesn’t mean it will play copy-protected Blu-ray movies because, as you’ve guessed, it’s not HDCP compatible. The same goes for your monitor. HDCP is a digital-rights-management scheme that requires a digital handshake at every stage of playback, from the disc to the videocard, and from the videocard to the display. Fortunately, there’s an easy fix. It’s not free, but it’s much cheaper than replacing your videocard and your display. Buy SlySoft’s AnyDVD (49 euros) and AnyDVD HD Option (30 euros). Install this software on your PC and you’ll be able to play back any copy-protected DVD or Blu-ray disc without an HDCP-compatible videocard or display.

You can have all the right connectors yet still no high-def signal going between your computer and your monitor. Thanks, copy protection.

You should be aware, however, that decoding Blu-ray video is extremely processor intensive. Your 7600 GS will rely on the host CPU for much of this decoding effort (CPU utilization could range as high as 100 percent). Newer GPUs from both AMD (beginning with the RV670 series) and Nvidia (beginning with the G92 series) are capable of offloading the entire decode process from the host CPU.

Freeing up the DVR

I’ve got a Comcast DVR (Motorola DCT 6412) that’s chock-full of content I want to watch, but the hard drive is filling up faster than I can watch the programming. The cable box has a number of connectors, including FireWire, Ethernet, and USB. I’ve heard rumors that there’s a way to download content off of the hard drive in the box but have not been able to get it to work on my Windows XP laptop (a Dell E1705). Any ideas?

Are there any legal issues involved? Lastly, there’s a lot of HD content on the DVR, but my laptop doesn’t have an HD writer. Can something be done to make the HD content work when played on a laptop, or is it just too much bandwidth for the technology I’ve got?

—Michael Collins

The Doctor knows you can plug a USB hard drive into a Dish Network DVR, but he doesn’t think Comcast has ever activated the USB ports (or the FireWire or Ethernet ports either, for that matter) on its set-top boxes. The Ethernet port on the Dish boxes is active, but only for downloading on-demand movies over the customer’s network via broadband (you can’t transfer files to a PC over the network).

So, in short, your content is locked to your Comcast box. If you want to expand your ability to transfer TV programming, you should look to another service, such as TiVo.

SUBMIT YOUR QUESTION Are flames shooting out of the back of your rig? First, grab a fire extinguisher and douse the flames. Once the pyrotechnic display has fizzled, email the doctor at doctor@maximumpc.com for advice on how to solve your technological woes.

In the Lab: Gordon Mah Ung Cross-Examines CrossFire

Gordon Mah Ung — Tue, 29 Apr 2008 15:35:28 -0500

AMD's Radeon HD 3870 X in quad mode scales well for having four GPUs.

I’ve been skeptical of multi multi-GPU support since the days of Nvidia’s original Quad SLI. Back then, bad drivers, a lack of game support, and 30-inch panels that cost a month’s pay made the prospect unpalatable.

So when AMD sent us an Alienware ALX system decked out with four GPUs, I didn’t expect much. But the dual Radeon HD 3870 X2s in this rig performed pretty damn well. In a system sporting a 3GHz Core 2 Extreme QX6850 overclocked to 4GHz, an Asus X38 board, DDR3/1800 RAM, and Windows Vista, the double double-barreled 3870 X2s’ performance at ultra-high resolutions shocked the hell out of me. In 3DMark06, Call of Duty 4, and Unreal 3, I saw a roughly 40 percent increase in frame rates going from one Radeon HD 3870 X2 to two.

At lower resolutions, closer to reality, the four Radeon GPUs didn’t up the ante quite as much at 1900x1200, but there was still a healthy 20 percent boost in COD4 and UT3. That’s probably not worth filling that second slot, but at least the setup offers decent scaling. The Radeon HD 3870 X2 ain’t perfect, though. Driver problems initially plagued our preview of the cards, so our assessment is that this quad-GPU solution isn’t quite ready for prime time.

It’s not much of a secret that Nvidia has its own second-gen Quad SLI coming out. It will use two new dual-GPU cards dubbed GeForce 9800 X2. It’s obviously too early to say which will be faster, but the quad Radeon HD 3870 X2 at least presents a respectable dual-card solution for folks who want to build a high-res gaming box using an Intel X38 or even X48 chipset.

CrossfireX Performance
	CrossFireX	Single Card	% Difference
3DMarkOverall 2560x1600, DX9	21,050.0	12,889.0	38.8%
3DMark06 HDR1 Canyon Flight 2560x1600, DX9 (fps)	52.7	30.0	43.1%
3DMark06 HDR2 Deep Freeze 2560x1600, DX9 (fps)	51.3	26.0	49.3%
Call of Duty 4 2560x1600, DX9 (fps)	93.0	73.0	21.5%
Unreal 3 CTF-OmicronDawn_Bot 2560x1600, DX10 (fps)	118.0	65.6	44.4%
Unreal 3 CTF-OmicronDawn_Bot 2560x1600, DX9 (fps)	120.3	68.5	43.1%

MSI R3870 X2 T2DIG

Michael Brown — Mon, 03 Mar 2008 18:54:01 -0600

AMD’s Radeon HD 3870 is a fine GPU for the money. It doesn’t outperform Nvidia’s GeForce 8800 GTX, and it lags far behind the extravagant 8800 Ultra, but it does deliver a phenom— er, make that a tremendous price/performance ratio.

So what happens when you put two of these parts—each with its own 512MB frame buffer—on a single board? You get a Radeon R3870 X2. The result isn’t as spectacular as you’d expect, but MSI’s implementation delivers plenty of bang for the buck. This card isn’t an Ultra killer by any means, but with a price tag of just $450, it doesn’t need to be.

There’s nothing mysterious about the R3870 X2—the two GPUs are exactly the same as those on a single-GPU card. Each one has 320 stream processors, a 256-bit memory interface, support for AMD’s Unified Video Decoder (for offloading HD and Blu-ray video-decoding from the host CPU), and dual-link DVI with HDCP on both links (to support the native resolution of 30-inch LCD panels).

If you care as much about high-definition video decoding as you care about gaming, you probably know that neither Nvidia’s 8800 GTX nor its 8800 Ultra supports those last two features. And unlike Nvidia’s new GPUs that do fully offload HD video decoding, the R3870 X2 supports the incremental updates to DirectX: Direct3D 10.1 and Shader Model 4.1 (although we believe this support to be unimportant right now).

MSI set the GPUs’ cores to run at 828MHz and the memory at 955MHz, a fraction faster than AMD’s reference-design specs of 825MHz and 900MHz, respectively. As with AMD’s 3870 X2 reference design, MSI’s board has two 512MB frame buffers, one for each GPU. AMD’s reference design and MSI’s implementation both use GDDR3 memory, compared to the GDDR4 memory found on single-GPU 3870 cards. AMD tells us there’s nothing about the design that would prevent its board partners from using GDDR4 memory or from increasing the size of the frame buffers (although we suspect there wouldn’t be a tremendous difference in performance from either design change).

A PCI Express 1.1 bridge chip sitting between the two processors effectively creates CrossFire on the card (with 16 bi-directional lanes for each GPU) without the need for a CrossFire chipset on the motherboard. There is, however, a single interconnect that will allow you to build a CrossFireX rig with four 3870 GPUs onboard, but that does require a CrossFire chipset. The board itself supports PCI Express 2.0, but AMD tells us that putting a PCI Express 2.0 bridge chip between the two GPUs would have delayed the product and wouldn’t have yielded much of a performance boost anyway.

Having all the components on a single board strikes us as a much more elegant solution than sandwiching boards together, which Nvidia did with its since-discontinued 7950 GX2. It also allows AMD to use a single cooler, which is located at the very end of the board and exhausts outside the case, for both GPUs and both frame buffers.

You’ll need both the six-pin and eight-pin power connectors if you intend to overclock a 3870 X2 board.

Having a single fan not only renders the card nearly as quiet as a single-GPU configuration but also avoids the need for twice the electrical power. The R3870 has two auxiliary power sockets onboard, one six-pin and one eight-pin, but only the six-pin socket is needed for normal operation. If you intend to overclock the board, you will need to send power to both of them. In our tests, our 3870 X2 test system consumed about 170 watts at idle and around 275 watts under load, compared to the 3870’s 117 watts at idle and 208 watts under load.

We periodically update the games we use for videocard benchmarking, but we’ve stuck with the Shader Model 3.0 tests in the artificial benchmark 3DMark06 as a means of providing continuity. The results we’ve seen with the 3870 X2, however, indicate that the benchmark has finally outlived its usefulness: The 2x performance boost it delivers there doesn’t jibe with the frame rates we saw in actual games. In fact, there was virtually no performance scaling in Crysis at all with the 3870 X2 when compared to a single Radeon 3870.

The 3870 X2 is a good solution, but it doesn’t solve the fundamental problem with dual-, tri-, and quad-GPU systems: Their performance doesn’t scale with every game—including high-profile titles like Crysis that you’d buy these cards for in the first place.