Secrets Of BIOS Tweaking

Sivar writes "While most enthusiasts are familiar with some settings that yield significant performance benefits, many other BIOS settings remain poorly described and may unknowingly play a crucial role in system performance and stability. Ars Technica has an excellent article describing some of the most obscure settings, useful not only for performance, but for tweaking stability and hardware compatibility as well."

Comments

USB Keyboard And LILO

[N8F8]

Just a tip: If you have trouble booting LILO with a USB keyboard try enabling Legacy USB support in the BIOS. It worked for me on a Dell GX240 Optiplex when all I would get is a Keyboard failure notice. You may also have to turn off "halt on error".

PnP

[Anonymous Coward]

Disable that pesky PnP in the BIOS. Could've saved quite a bit of hair pulling on a FreeBSD 4.6.2 install.

Re:PnP

[turgid]

That's good advice, since modern kernels like *BSD and Linux can and do prefer to take care of configuring PCI devices themselves. It's only users of DOS and DOS-based versions of Windows that need to have this feature enabled, AFAIK.

I liked this article the first time i saw it...

[diesel_jackass]

THG has had a good BIOS guide as well:

http://www6.tomshardware.com/mainboard/97q1/970101 /index.html

and also a guide on BIOS tuning:
http://www.tomshardware.com/howto/01q3/010725/inde x.html

Re:I liked this article the first time i saw it...

[Wanker]

Speaking of Tom's... After following the BIOS article (which is a very good read), the first forum I stumbled across was:

http://arstechnica.infopop.net/OpenTopic/page?a=tp c&s=50009562&f=77909774&m=8400979235

In this forum the poster makes a pretty convincing case that the photo of the P4 3.3GHz chip in the "Hot Contraband: P4 With 3.6 GHz" article was forged. A subtraction analysis (described in detail in the forum) shows a nice little black box indicating they just copied a "3" to make the 3.3GHz photo.

In my mind, this throws a lot of doubt on anything posted on Tom's hardware. Which is really too bad-- I liked that site a lot.

BIOS?

[Lawst]

Hmm, BIOS means Bandwidth Instantly Obliterated by Slashdot?

Is it that hard to supply a BIOS setup manual?

[The Moving Shadow]

I always wondered about the fact that (almost?) no manufacturer supplies a manual describing their BIOS setup in detail. Most of them mumble something like: "you can press DEL to fiddle around with things you will never comprehend during your lifetime" and that's about as much help as you get. They of course also have included this neat *sarcasm;)* help function in most BIOS setups that displays the context sensitive help. I don't know how often i pressed F1 in vain just to see the message: "Help: Enable A-20 Gate. PG UP=on PG DN=off" Stuff like that...

There sure has a reason to be for the lack of good documentation. The best manual uptill now was the one that came with my old ABIT KT7a RAID mobo, but maybe that's because back in those days it was considered a home "tweakers" board. So mr. Phoenix, Award, AMI, if you read this, please o please bundle nice manuals with your BIOS setups for us endusers to use, instead of hoping for great sites like Ars Technica and Tom's Hardware to help us out.

Re:Is it that hard to supply a BIOS setup manual?

[larien]

I can understand the lack of help within the BIOS; after all, you're trying to keep the BIOS footprint to a minimum and adding help text just increases footprint.

However, that isn't really any excuse for not documenting it elsewhere, other than some ID10T getting ideas that tweaking the BIOS is a safe thing to do...

Re:Is it that hard to supply a BIOS setup manual?

[Zocalo]

I've always found Asus (they use Award's BIOS) to be another notable exception in this regard, and there are a few others I'm sure. It's definately not the the norm though, and BIOS help does indeed suck universally, except for some of those stupid BIOS-on-a-cutdown-Windows some Tier 1's used to use, but then, it's not hard to document the three available settings well, is it? :P

Of course, since there are really only half a dozen or so BIOS vendors, the mobo vendor manuals are pretty much interchangable, and /. not withstanding, I've found several web sites post documentation for them besides this one via Google.

Re:Is it that hard to supply a BIOS setup manual?

[pclminion]

I don't know how often i pressed F1 in vain just to see the message: "Help: Enable A-20 Gate. PG UP=on PG DN=off"

In case you are still mystified about A-20, it is an ancient holdover from when machines didn't have a high memory area. In 16 bit arithmetic, incrementing 65535 produces 0, and many programs took "advantage" of this fact. However on newer systems there was an extra address line, and if it was enabled this address "rollover" didn't happen correctly. Result: legacy programs crashing.

A-20 is automatically enabled by all 32-bit operating systems anyway. The option in the BIOS is there to control HOW that enabling happens. Modern chipsets can enable A-20 directly. Historically, however, A-20 was logically AND-ed with a pin on the keyboard controller, so in order to enable A-20 you had to reprogram the keyboard controller.

I love PCs, they are the only hardware I've encountered where you have to program the keyboard chip in order to enable high memory access. :)

Re:Is it that hard to supply a BIOS setup manual?

[Artifex]

There are some problems if you think in the long term - a typical BIOS wouldn't necessarily get outdated, but one with support for specific file systems would. Or could.

That's why BIOS is usually flashable, right? =)

Seriously, yes, having a built-in set of better diagnostic and prep utilities would be great. Just think of all those Gigabyte motherboards out there with dualie BIOS on the board, and what you could put in all that extra space if you could somehow access it.

On the other hand, while ROM does sound cheap, just remember that a $1 part undoubtedly costs more money to add to a board, probably more like $1.50 when you factor in the extra work in getting it on the board. Multiply $1.50 by 100,000 boards, and suddenly you're talking real money, and that's wholesale, way before retailer markup. Sure, hobbyists would be happy to pay the extra $1.50 (or even $5 or $10), but if they only buy 5-10% of the boards, the decision to include the part suddenly becomes much more difficult. Your average large VAR could care less about special BIOS options, and doesn't need to format drives in individual machines the way we do it because he has OEM licenses from MS, tapes of their latest OSes and software packs, and machines for batch-writing drives with the OS and software pre-installed.

P.S. My dollar figures are used to show the issue of relative costs only, and are probably nothing like the real costs.

sorta useful, but short of the mark

[stratjakt]

about the memory hole at 16M:

"Sound Blaster Live cards like this to be enabled. It essentially removes 1MB of your RAM, so consider replacing the sound card instead."

Yeah, it would suck to have only 511 megs available. I'm not giving up my SB Live any time soon, at least not till I decide to get Audigy. It does mention that this is for SB16 emulation, but doesnt clarify by saying you only need that if you want legacy DOS soundblaster support. It's actually wrong: SB16 emulation happens transparently, SB16 pseudo-emulated 'mode' requires this. (Booting into plain DOS rather than running in a Win2k/XP console)

On the Video RAM Cache:

"Disable this. You don't want to be wasting the L2 cache on fast video RAM when you have slow system RAM to deal with"

Not every box has a sooper-dooper fast mega-card in it. I have boxes with old Cirrus Logic and Mach64 cards in 'em. And not every PC is equipped with AGP. Enabling this can yield a performance boost on some hardware, a little more detail here would help.

I dont have time to analyse the whole thing.. It got slashdotted before I could make it through, and I'm not a know-it-all techie geek. I just have enough rope to hang myself with, as the saying goes.

But like most 'BIOS' guides I've read, this gives alot of info on 'tweaks', with little mention of the damage that the wrong settings can do. I've seen RAM, PCI and AGP cards get fried because the user unwittingly 'overclocked' it.

They always just tell you what the fastest possible setting is, but never mention "if your hardware doesn't support it, you'll wreck it". Personally I think sacrificing stability for the sake of a 1% theoretical boost in performance is bad mojo.

There's also a disproportionate amount of Soundblaster-bashing going on here. Apparently my SB Lives have been crashing my systems and suffering poor sound latency for the last couple of years. Funny that I never noticed.

Re:sorta useful, but short of the mark

[stratjakt]

yeah, thats true.. There's a backwards-compatible mode that SB Lives can use to act like an SB Pro for the odd guy who still runs pure DOS and needs to play Duke Nuke'm. Basically a 'pretend your an ISA card' thing, and IIRC it loads a driver (sys file) into this 1 meg hole to look like an SB Pro.

I'm no driver progammer either, but I know that this setting doesn't affect SoundBlaster Live under linux, WinNT/2k/XP. Or even 95/98/Me for that matter.

The article suggests that SB Live is somehow flawed in this respect, which to me just sounds like the author is making up a reason to hate SoundBlaster.

(The SB Live does have legitimate problems which are beyond the scope of the article. It doesn't like to co-exist with a secondary sound card, for example.)

Re:sorta useful, but short of the mark

[stratjakt]

Umm, I did read the article.

Nowhere does the article say it's a "bios giude aimed at tweaking a pc for gamers", it claims do de-mystify the BIOS for PC users in general. It *is* just another "tweak" guide, but purports to be more. That was my point.

And a disclaimer saying "you can ruin your os/hardware, we are not responsible" isn't enough for me. I wan't to know how, when and why.

Re:sorta useful, but short of the mark

[Zathrus]

And not every PC is equipped with AGP

Well, every PC built in the past 3 or 4 years is... and, frankly, if your main PCs are older than that you're not likely to be reading ArsTechnica or something about a BIOS tweaking guide.

But like most 'BIOS' guides I've read, this gives alot of info on 'tweaks', with little mention of the damage that the wrong settings can do

Obviously a problem... I haven't read the article yet (didn't feel like it this morning, and it's toast now), but they should really mark the settings that are potentially dangerous. Screwing around with your RAM timings, CPU clock, etc. can release the magic smoke awfully quickly.

There's also a disproportionate amount of Soundblaster-bashing going on here

Not really. Creative Labs has long made the worst hardware they could get away with, and did so thanks to having created the original standard for PC sound. They've never been high quality cards, and have often caused problems with other hardware and software. Go talk to someone who tried putting an SB Live in a dual processor NT4 system about it for example.

Frankly, if you're looking for a new soundcard then there's little reason to buy Creative. For general use (games/music) both Hercules and Turtle Beach make better cards for less. For games alone, Hercules or Philips are better (Philips mentioned purely due to QSound). If you're talking about just playing music, doing a home theater PC, or mid to high end audio then a more expensive card that does real 24/96 or 24/192 audio is preferred - M-Audio and many others fit the bill here.

I do think that the incompatibility bit is somewhat overstated (I don't have any problems with my SB Live or my much older SB64 ISA), although SB's are notoriously bad about sharing PCI IRQs and the like, but the poor sound quality and total lack of compliance to industry standards are not. The digital out on the Live series doesn't comply to any spec known to man -- its voltage is roughly 10x the allowed spec. Even the Audigy continues to resample everything to 48 KHz, which plays hell with CD Audio, and their claims of 96 KHz sampling rates are deceptive at best (only applies to the digital outputs, and only sometimes at that).

If you want more details, I suggest either the PC AV Tech or [H]ardOCP's Audio forum. If you're interested in HTPC's in particular, then take a look at AVS Forum's HTPC forum.

Let me guess..

[tangent3]

Optimizing your BIOS settings is not enough to prevent your server from being slashdotted...

LinuxBIOS is the Best System Performance Tweak

[LuxuryYacht]

Replacing your legacy BIOS with LinuxBIOS yeilds the best overall system performance gains.

SPD, ACPI and PCI init and config is still quite a mess these days. Using an open source BIOS allows system performance to be tuned and maximized beyond what the usual legacy BIOS setup screens offer.

Aren't There Better Ways?

[Spencerian]

The BIOS of the x86 world, in my opinion, is one of the reasons why we struggle but never quite reach a integrated architecture for PCs. Lord knows I've fought with quite a few of them, and hated having to remember to disable this in order to use that, with no guarantee that my change would work all the time.

Shouldn't our computers know what hardware it holds and configure itself automatically nowandays, with little to no user interaction? It would make all that "plug-and-play" stuff that's taken for granted on Macintosh systems, to site an example, true for my PC game box as well.

The technology is already here in the form of Open Firmware, which Apple uses as well as Sun. There is at least one company that has OF implementations for x86, but so long as Intel has a vendor lock on how motherboards are designed for their chips, I don't see this annoying and archaic method of maintaining a board going away any time soon.

OF is configurable enough for crazy whiz kids, if necessary. A better BIOS would make things a lot better for the OS and bring a better experience. Why can't we break out of the BIOS hell? Hadn't we learned the lessons from the Y2k-incompatibilities that some BIOS had, among other headaches?

Best BIOS site on the net...

[xTK-421x]

If I have an obscure Taiwan motherboard, this place almost always has a link to find the latest BIOS for it:

http://www.wimsbios.com/

I'm sure it's old hat for most people here, but some people will probably need it to find their latest bios to use this guide.

for more information...

[sc00p18]

Go relax with some good ol' Adrian's Rojak Pot.

Actual link to linuxbios

[casio282]

Strange that the linuxbios link provided above is to a commercial website. Here's the link to the proper linuxbios site, at linuxbios.org.

Where do I find bios?

[pepperino]

Is it under File or Edit? I didnt see it under View or Favorites. I clicked on the Help one but it just laughed at me.

I find the author rather uninformed.

[Anonymous Coward]

"Back then, we didn't have drivers"

yes we did.

"Long before the term "API" was born"

I have a hardware book on the original 8088 IBM PC published in 1985 that includes specs on the bios and boot loader software, and talks of APIs.

"You could call BIOS ROM routines to handle video, PC speaker beeps, the keyboard, and so forth."

That is, if you only wanted your program to be able to run on that ONE model of PC. To get to hardware, nobody programmed to teh BIOS, they programmed using DOS interrupts.

"Remember, in those days, people didn't build their own systems"

Yes we did. I replaced the mobo on my XT with a 386 mobo. By then the only original components in that box were the case, power supply, and keyboard.

The original 8088 mobo used jumpers and dip switches where we now make the adjustments in BIOS.

Maybe he's a whiz on modern BIOSes, I don't know. But he's sure clueless about primitive PCs. Knowing this, I have to take everything he says with a grain (or whole damned shaker) of salt.

Bios "Help"

[gnovos]

I love the "helpful" BIOS messages...

o ACPATI IEEE 9.0 compatability : ON | OFF
Help -- This settiong turns on or off ACPATI IEEE 9.0 compatability.

o CPU LIMIT PRIMER : FREE | POST | RETRAIN
Help -- This setting sets the primer for the CPU LIMIT

o DARNING PORT FLANGE : WITHIN | OVER | COMPLIANT
Help -- This setting alters the darning on the PORT FLANGE

It's a DOS thing (you remember DOS, right?)

[Reziac]

My SBLive doesn't do any of that nasty latency-related stuff either... but normally you'll only see that on VIA chipsets (it's a well-known issue there) and I run pure Intel chips. And mine works fine so long as its lame-assed DOS emulation is disabled. When that's enabled, it NUKES Windows, and doesn't work anyway.

As to the 15/16MB memory hole, IIRC (and IIUC) when it's enabled, it prevents any DOS program from using memory above that point, because DOS can't jump the gap like a fully protected-mode OS can. If you run big DOS games or databases in real DOS, this can be an issue, in which case the memory hole must be disabled or stuff won't work or will be really slow due to swapping to disk when it runs out of the first 15MB of RAM.

So it doesn't exactly "remove" 1MB of RAM; it limits DOS on your system to a mere 16MB usable RAM, no matter how much physical RAM you have.

Some older memory managers do the same thing.

Why does the machine even ask you these questions?

[raytracer]

Honestly, isn't your brain full of important things to think about? Wouldn't you like a machine which didn't needle you about details of its own operation that you don't understand? When you hop in your car, you don't expect to have to set fuel intermix ratios and timing to get out of your driveway, yet your computer manufacturer seems to think that you probably know better than they do what all these settings should be.

Consider the memory options listed in the article. Do you know what the 15M-16M memory hole is? Autodetect DIMM/PCI Clock? Bank Interleave? The article says Bank Interleave gives you a massive performance benefit, why then have an option to turn it off? What's the point?
Data Integrity Mode? Don't you think it would be nice if your computer knew whether it had ECC ram in it or not? Delay DRAM Read Latch? The article says that if you don't set it right, you can get crashes in your machine. Golly, don't you think manufacturers should just make the computer get it right?

Memory options go on and on and on. The only thing I want to know is that my computer can read whatever memory is installed at the highest reliable speed. I shouldn't have to tweak the no less than two dozen different settings to
get my machine working reliably, and those are just the memory related ones. A similar number awaits in the PCI and AGP configuration settings.

Legitimate uses of the BIOS are perhaps to enable or disable peripherals and to choose boot devices. It might also be nice to have a mode which shows what peripherals are installed. Other than that, I'm perfectly willing to allow the computer to pick out its working parameters. If the resulting computer proves to be unreliable, then the manufacturer should be out of business for making crappy computers.

Rant concluded.

Weird BIOS settings on ASUS A7V333

[fotoguzzi]

I was poking around the Vcore settings on my ASUS board with an Athlon XP 1700 processor. The settings range from the expected 1.675V - 1.85V, but if you hold down the righthand Alt key and then Page Up and Page Down, you get values ranging from 500kV to 1.5MV in 50kV intervals.

Does anyone know why these settings should exist?