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Fairly new to Intel-chipset boards is a feature known generically as the north bridge strap—Asus calls it the FSB Strap to Northbridge and Gigabyte calls it the System Memory Multiplier—and it can throw us old-timers for a loop. The north bridge is actually its own little processor, which, on Intel chipsets, is tied, or “strapped,” to the front-side bus and memory. It’s possible to change the speed of the strap—both Asus and Gigabyte, for example, let you manually select strap speeds from 200MHz to 400MHz.
There are two practical uses for this. First, by manually setting the speed of the north bridge strap, you can change the memory clock speeds available on the board. As mentioned above, simply increasing the front-side bus speed will automatically increase the speed of the memory—perhaps far beyond what your module is rated for. By notching the strap down, you can get your RAM operating within spec while leaving the FSB at its overclocked state. Why not just let you pick the RAM speed you want and be done with it? The theory is that the straps are already preconfigured to offer the best performance ratios, which are preferable to those you set on your own.
The second purpose of the strap: The internal clock in the north bridge will gradually tick up as you increase the front-side bus of your system. It’s somewhat similar to the gear ratios in a car. As you rev up the front-side-bus speed, the rpms of the north bridge can get out of spec and cause a crash. The strap will adjust the speed of the north bridge clock independent of the FSB. The general rule of thumb for overclockers is to use the lowest strap available that runs your RAM at the speed you need. This should enable higher front-side bus overclocks.
The upshot of this is to run in auto mode if you’re not overclocking and leave it to the board engineers. If, however, you are overclocking and seemingly hitting a front-side bus wall that no amount of voltage will address, try lowering the north bridge strap to see if you can push the FSB even higher.
If you’re an AMD user and you’re confused by all this north bridge strap stuff, you can just ignore it. Since Phenom CPUs feature the memory controller directly in the CPU core, there is no memory controller strap to futz with. What is confusing is the ganged or unganged mode available in Phenom boards. Phenom CPUs feature two separate memory controllers that can be run ganged or unganged. Generally, you’ll want to run as unganged to let the controllers operate independently for best performance.
Some motherboards have begun offering the ability to tweak the “clock skew” for RAM. In a nutshell, clock skew is the variation in speed of a module’s individual signal paths to the memory controller. Skew is the result of the signal distortion caused by the traces in the motherboard, the cleanliness of the power going to the board, and the RAM that’s in use.
Tweaking the skew settings can help increase stability when you’re pushing the chipset and RAM to its limits by overclocking. It’s a game of trial and error with skew settings, but if you’ve got the time and energy, it could help you achieve the few extra megahertz you were hoping to get out of your system—just be ready to roll up your sleeves and run the POST, crash, reset, POST routine. If you’re not overclocking, however, you can just ignore these timings.
When the BIOS is finished prepping the hardware, it doesn’t necessarily have to hand control over to the OS. Instead, many companies are now inserting a pre-OS, or preboot, environment on their boards that the PC can boot to before the OS.
These environments are stored on small bits of flash RAM embedded on the motherboard and can contain a basic Internet browser, Skype client, and even the ability to access your Outlook email and contacts. Although referred to as a pre-OS, the majority of these environments are embedded Linux.
The feature has long been found in notebooks, but it’s now migrating to desktop motherboards. Currently, Asus is the primary adopter of the pre-OS and has it in many of its motherboards. In our experience, it’s a novelty that can occasionally be useful—say, for example, you need information from the Internet faster than you can wait for the OS to load. With Asus’s ExpressGate pre-OS you can be in a browser in one minute instead of five. Granted, that’s a rare need, but we can see a pre-OS browser being useful for, say, downloading utilities, drivers, or fixes to a broken or infected OS on the hard disk—though currently, none of the implementations we’ve seen allows you to save files to your machine.
Comments are closed on this article
dcdannyf
June 16, 2009 at 10:14am
Thanks for the info! It's very helpful, and i've seen BIG improvements in my AMD's processor speed and overall performance! You guys know everything about BIOS. BIG Danny :)
DePat
October 23, 2008 at 1:49pm
Thank you for the article on tweaking the bios. I however think that before asking the public to "tweak" the bios, it will be a good thing to understand what all the "stuff" in the bios is. There is an article titled Understanding the bios on your website but when I click on it I get only the title, nothing else. I understand that your readers are "more knowledgeable" than the average consumer, but at the same time, if you do not provide basic information how will the rest of us catch up? Although I do not consider myself as a novice when it comes to computer (I might be just a short step above), I am a novice when it comes to "bios settings" and I do not have the time to research all that information. I will appreciate, and my guess is that I will not be the only one, if you could locate one of the most extensive or complete or detailed bios that you can find and explain what the acronyms mean and their purpose, line by line, page by page, with corresponding pictures and figures. That article can become the basic document that will be updated and modified based on the next completed or detailled bios you find during your testing. This article can then be permanently posted on your website.
If such an article is done and regularly updated, I am sure that you site will become a destination for computer "newbies" and veterans alike in the search for "basic knowledge" and understanding. In turns, this increased traffic will give a boost to your subscription base and will free you from "EVER AGAIN" considering advertising like the "enlargement" advertising a while back.
Keep up the good work
DePat
Deanjo
October 06, 2008 at 11:26pm
"AHCI is supported only by Intel and ATI at this point and not by Nvidia."
How old is this article? FYI, Nvidia's boards DO support AHCI (At least the AMD 7 series). ATI on the other hand has an extremely spotty record with their AHCI implementation ranging from data corruption, disappearing drives, NCQ issues and only 32-bit mode support.
yr
October 06, 2008 at 4:22pm
It would have been nice if MPC would discuss the "advanced timings" (as well as tRFC). These timings are VERY important for getting MAXIMUM CAPACITY out of your memory slots.
I just installed 1gb DDR2 Corsair Dominator 8500s in all 4 slots of my 680i (1066mhz), and 2gb DDR3s OCZ's (1600mhz) in all 4 slots of an MSI X48, and setting these timings high (specifically tRC & tRFC) is the ONLY way to get a stable system!!
Check out the forums by Corsair, OCZ and several other memory makers; these advanced timings are the only way to get a stable system!!!
Hope that this helps someone; maybe MPC can help explain these timings (I know that MSI can't.)
Keith E. Whisman
October 06, 2008 at 3:03pm
It's a good rule of thumb to disable ports and features like onboard crappy audio that isn't going to be used. I think that the article is good and shutting alot of crap off simplifies things. Less is best. Less chances of Murphy's law stepping in and mucking everything up. Like Kiss (Keep it simple dumb ass).
rayatwork05
October 06, 2008 at 10:37am
im surprised maxPC didnt cover disabling unneeded devices to increase available RAM.
didnt cover BIOS flashing either. hrmm.
Muerte
October 06, 2008 at 1:21pm
I think they were going specifically for speed increasing tweaks for the processor, motherboard and RAM. While those tweaks will increase overall performance of the computer they do not specifically speed up or add to the computing power of any of those things.
yr
October 06, 2008 at 4:24pm
But stability is always important. MPC will KILL a PC rating because of instability. Some of these tweeks can prevent or create instability and knowing what to do is as important as what NOT to do!
