Maximum PC

SATA III controller card I bought has two SATA III connections. Am I correct in assuming if I plug a device into BOTH connections, I would be cutting the bandwidth in half for each device??? If the card was drawing 500MB/s, each device would only get 250MB/s???

If the above is true, could I plug a second card into a PCIExpress port, plug only ONE device into it and get ALL the bandwidth to that device???

If I wanted my SATA III SSD plugged into one controller card and receive ALL the bandwidth from the PCIExpress slot, then download the info it gets into a hard drive that is plugged into a second SATA III controller card plugged into another PCIExpress slot.... would that be a good way to get the fastest download possible????

No. If you have 500MB/s available, you have 500MB/s total available to share between two devices.


You could, if you really wanted to.


No, because transfers are capped to the slowest speed, which is the HDD. On average they tend to be around 100MB/s, so your transfer speed between HDD and SSD will always be around that.

Sigh.... I'll say it again, you're not even comming close to that 500MB/sec on a single Vertex 3.

BTW, the only time I would recommend an add-in SATA III controller card for a single SSD is where the SSD is to be used in an old system that only has 1st generation SATA 1.5Gbps ports.

Bottom Line, if you're using SSD's & have a mix of SATA II & SATA III connectors, then any hdd's go to SATA II connectors (even if they are SATA III hdd's) & your fastest/newest ssd's go to the SATA III connectors. If you only have SATA II connectors, it's nothing to worry about unless you're running benchmarks 24/7.


He's refering to the limited bandwidth from a PCI Express 2.0 1x slot which is only 5Gbps per lane. A 1x card in a 1x slot can only hit a max of around 500MB/sec, which is why most of the add-in RAID controllers that work well are PCI-E 4x or PCI-E 8x cards.

I can attest to this. I have a Samsung 830 in my desktop in a SATA III port and another in my laptop that only has a SATA II port. The laptop is faster. And while I could say that sure, I don't put as much on the laptop as I do the desktop, but keep in mind, a brand new install of Windows on the desktop with no drivers installed or anything still needs the entire loading animation. On the laptop, the SSD only had the system restore image up, minus the bloatware, and the loading animation didn't even finish.

First, Klein I got the joke. Some people are just too slow.

Second, if I were to install a second SATA III controller card I would plug a SATA III SSD to it, not just a regular HDD.

Don't try, as I think it'll come naturally to you

At least that would work around the 500MB/sec limitation... but I'm going to post 2 images, one is a benchmark of a RAID-0 SSD array on a SATA III controller, the other is the same RAID-0 SSD array on a SATA II controller. Now the SSD's in this array are 120GB Mushkin Chronos, same generation as the Vertex 3, but with Asynch NAND instead of Synch NAND. By running in RAID-0 on the motherboard controller, read & write throughput is increased 95% - 98% depending on the exact controller used. This should show you how close you'll come to saturating the 500MB/sec bandwidth on a 1x controller card with 2 Sandforce 2281 based SSD's attached to it.




After viewing those two images, can you tell me why you need a SATA III controller card??? Care to guess which image is the SATA III controller? Can you tell me why I recommend you use the motherboards SATA II controller instead of an add-in SATA III card???

New, those puppies hit 420MB/sec read in RAID-0, but the images above are after 6 OS installs & 2 months of regular use on the current install.

Well you're wrong in two ways.

First, I wouldn't use a x1 controller card I purchased a PCIE x 2 card.

Second, I would NOT plug in two hard drives into the same controller like you did. Why the hell would I cut the bandwidth in half???? Defeats the whole purpose. Not very smart.

As cheap as controllers are and as many PCI slots there are, there is no need to plug any two devices into a controller card.

Run your benchmarks with a PCIE x 2 controller card with ONE SATA III SSD plugged into it. Then get back to me.

I think we went over this. If you're connected to a 500MB/s interface, and you have two devices on it, your total available bandwidth for both devices is still 500MB/s. If you have two devices that can chew up 500MB/s, but one is idle and the other is working hard, then that one device is going to work at 500MB/s. But if both devices are working hard, then yes, the bandwidth will probably average about 250MB/s for both by the time they're done.

Chaos, I pick the bigger number in the pictures you posted AND in the controller I buy. Everything bigger in numbers is always better. And adding two drives always halves the theoretical bandwidth given. Spinal Tap tells me that 11 is awesome.That's why the nVidia 6600 is so much better than that piece of crap 670. <- It's snark ya'll. You have to be more obvious and make it a glaring mistake as that sounded pretty logical and worth a try. Roberto obviously knows more than all the helpers have already suggested, so it's feeding the pig basically. He's already using fuzzy math...or is possibly baiting.

Maybe I have too much hope in the ability to grasp ideas and feed them myself, but sometimes you just gotta let go of the rope and let them fall down the cliff. However, the worst is this: One asks for help, given the best info you can build from, and refutes it without even trying it. Theoretical builds by theoretical builders with many debates before they use any of the tech. Yeah, I saw many of these drop outs in college. I can't speak for others, but this futile battle has been around, grows old, wears on a person that really wants to give help...and (IMO) why some elders are lurking vise posting. Decades of arguing with pigs gets old.

Kleink, don't try to be an ass or you become an ass...it's a sketchy slope I'd advise against I'd make a Padawan/Jedi/Darkside reference, federation changes...shit like that; but I can only preach the darkside these days. I can only warn you to keep helping kindly as best as you can (and many of you do well). Let us asses be asses and the wise will rise in MPC forums to build it again. Good advice builds forums and some of ya got it...

This guy, I'd let fall to page two and move on to someone wanting to learn.

If you want to learn, I suggest that you at least try to understand the concepts laid out in front of you... You can start by learning the terminology, then you can learn to read and comprehend an entire post, starting with this one. And don't tell me you've read every word, because if you did, you would understand that I would NEVER use an add-in controller card. I'll get to that later just to see if you are reading...

First things first, there is no such thing as an x2 card. x1 refers to the PCI Express x1 slot on your motherboard. The 'x' means 'times' (as in 2x4 = while the number refers to the number of PCI Express connector 'sets' on the motherboard for your add-in card, and they only come in 4 flavors: x1, x4, x8, and x16. A x1 card has one set of power and data connectors in the PCI Express slot on your motherboard, a x4 card has 4 sets of power and data connectors in the PCI Express slot on your motherboard & so on.

Secondly, don't ASSUme, all you're really doing is making an ASS out of yoU. My previous comments alone would give you a very strong indication that my drives are connected to the motherboard connectors. Having a 990FX chipset, I have Six native SATA III connectors to use, so your thoughts & ideas on my connections are totally f'd up.

I'll now post the full image of the SATA III RAID-0 setup.


You'll notice that ATTO shows the RAID array surpassing 900MB/sec. Yet AS-SSD is within 5% of the real-world file transfer rate This means, you can connect two Vertex 3 SSD's to the two SATA III connectors on your x1 controller card, and still not surpass the 500MB/sec limitation (in real-world transfer rates) of the x1 PCI Express slot. It further means, that you never needed a SATA III controller card, that as I told you early on, you can use the Motherboard connectors. Each motherboard SATA II connector has a max transfer rate of about 300MB/sec after overhead, & with 2 SSD's connected & operating simultaneously (as in a RAID-0 setup), the integrated motherboard SATA II connectors have a combined 600MB/sec upper limit.

Now, my RAID arrays in both instances are connected to 990FX chipset's integrated SATA III controller which has 6 lanes capable of a combined 3.25GB per second transfer rate. In the case of the SATA II test, it's simply a matter of switching BIOS to SATA II mode. Though this image is from a previous install when the drives were operating a little better, you can see similar transfer rates at SATA II, but notice ATTO only reaches about 530MB/sec.


At this point, I don't care if you waste all your money on stuff you don't need... that's your decision to make, but it's still a decision I hate seeing & committing. Yes, I've been guilty of this myself. However, there's one place I'll never waste money, or rather one thing I'll not waste money on, that being add-in controller cards. Intel & AMD both have outstanding integrated SATA controllers. They're so good in fact that you have to pay more than the cost of a decent new motherboard to get an add-in controller that is better than what Intel & AMD already have in their chipset. For a RAID controller that will get you a measurable increase over the integrated controllers (as in more than 1 or 2% increase), you'll have to spend $300+ & get an PCI-E x8 hardware (on-card processor) based RAID controller card. This is one of the reasons that you won't find a RAID card in Maximum PC's Best of the Best hardware list... But if they did have one, it would be this $665 one: http://www.newegg.com/Product/Product.a ... 6816118160

And with that, I wash my hands of this thread. If you want to learn, I will help you where I can. But if you want to come here & throw around a bunch of B/S & ignore what has already been answered, well I won't have any more part of it.

thank you, im always willing to learn, its a lifelong quest.

peace

ed