View Full Version : Question regarding my settings of RAM speed....

23rd Oct 2002, 23:42
Peter...I know you should be able to tell me something regarding my chip settings in the BIOS/CMOS window for my RAM type, etc. I know my RAM is 7.5 ns and my CAS is 2. So I have the CAS already set but the ns speed is what throwing me off. At present it was automatically set by the BIOS at 8-10 and when I click on that selection I get a window with the following choices.

Normal, Medium, Fast, Turbo back to SDram 10ns...currently it shows Normal. Shouldn't I be able to use Fast or Turbo with mine? It doesn't really explain how those choices apply to RAM...I don't understand what Fast or Turbo means in this terminology? So could you help me figure out if I can use either one of these settings to get better performance from my RAM? :) In case you need to know as well, it's PC133 I bought from Cruical when I upgraded everything last year. Thanks and Good Hunting!

24th Oct 2002, 01:04
1> Check your MOBO manual. It will tell you what RAM it will accept. The fact that it fits the slot does not always mean the MOBO will run it at the right speed. By that I mean 133 will run in a 100 MOBO but you can't kick it to run at 133 (overclock) the board sometimes.

2> Auto reads the chip itself for the information then the MOBO sets itself to as close to the chip specs that it can.

3> Check the Crucial website. It should tell you the NS rating of the chip. If it is 10-ns you should leave it there if it is faster then try the Turbo setting. In most cases AUTO is the safest and best.

24th Oct 2002, 04:53
Most DIMMs in the past 3+ years have SPD (serial presence detect) which reports its specs to the BIOS when queried. So set your BIOS memory settings to auto (for those that have an auto setting). The CAS setting may not have an auto setting; in that case, set it to match your CAS spec for your DIMM. Be careful with DIMMs that say they are CAS-2. Many are actually CAS-2.5 and the BIOS should be set to CAS 3, not CAS 2.

If you want to use the "turbo" settings for memory, make sure you test it thoroughly for a week. Run all your software, including games, and anthing that might exercise memory more tightly. Windows NT/2000/XP itself will show up memory problems that Windows 9x/ME will not report. Don't install ANY software or make ANY significant changes to your machine during the testing period.

While some motherboard manuals give some hint as to what their turbo settings do, they are technical manuals and usually the information is so vague that you just have to change and test to see if they work. The difference in speedup using BIOS memory tweaks is so low that I've never bothered with doing more than using Auto for whatever settings have it in BIOS and making the CAS setting match. The most that I've seen for a speed boost between the safest settings and those that push the memory until it starts to get flaky is about +17% but that's only in the purest memory benchmark. For applications, I rarely saw more than a 5% speed boost and most the time it was only 2% and that's within the range for error in test measures, anyway.

Many folks overclock their PC-100 memory by setting the CPU bus at 100 MHz and then incrementing the memory bus by +33MHz. While overclocking of CPUs can make them flaky, especially Intel CPUs (and with AMD CPUs you had better severely improve your cooling if you overclock them), a lot of PC-100 memory can be overclocked - if your mobo has seperate CPU bus and memory bus settings (or the memory bus speed is incremented over the CPU bus speed). A better motherboard with a faster memory architecture and faster chipset can give you a speed boost, too.

24th Oct 2002, 19:51
Hi Vanguard...thanks for dropping in :) Yes...my manual is actually written pretty well (from Abit) but they really don't say much about RAM stuff. The only thing I gleened from it was that the BIOS will default to 8-10ns and CAS 3...anything different you have to change manually. That's why I'm in the dark as to these particular settings that I found early on. In the case of CAS...I do know my sticks are good quality and bought from Crucial...not a generic. In addition to perhaps using the fast setting, I've also been taking a second look at another selection under CPU settings by the name of: Enhance Chip Performance. Currently it's disabled but says to enable would give higher system performance. Don't see why I couldn't use that setting?

Ha, ha I read an article the other night on the Web about OC'g and such and it seems my chipset, Via's 133a, and the Duron is very good for boosting performance....hmmmmm? LOL Now if I only knew someone who knew what he/she was doing... OHhhh the possiblities of going past 1.2 ! In fact my board does allow OC'g as it offers different clock/multipliers/voltage changes ;) I do understand about the need of good cooling measures in going that way...but like I said...it would take someone more knowledgable than I to try it :D I just wish I knew how cause I think I could get more out of it, especially with the new CPU I'm going to put in it. I was reading VIA's BIOS upgrade section and getting a newer 4-1 download and it seems for my board they did do some enhancements for the Athlon 1.4 to be used on this board whereas the limit was 1.2 as well as the board was ready for 200FSB when it would be made available. Well of course now it is and I'll be able to use that as the Duron I'm getting has the 200FSB capability also :) Now all I have to do is figure out how to do the BIOS upgrade :rolleyes: I know there are instructions for it but I'm a little tenuous about doing it. It could get so easily screwed up if not done right! :eek:

In the past when I tried to get my older brew's BIOS upgraded the tech at the time said it wouldn't take and so I had to end up buying a new BIOS chip to install. Wish I could do the same for this one...would be so much easier and a foolproof method but I don't know where I could find one? Don't even know if I could get that info from Abit's ppl? Possible I guess? My MOBO by the way is an ABIT KT7A with VIA's 133a chipset. So there you have it and maybe you have an idea about my other question as to CPU performance and enabling that selection? Don't think it would hurt anything, do you? Ta and Good Hunting!

25th Oct 2002, 02:45
Hi Huntress,

With 7.5 ns (nanoseconds), you have PC-133 memory, so overclocking PC-100 is not an issue. The first thing to do is to make sure your PC-133 memory is running at a bus speed of 133 MHz, its rated bus speed. if you have a 133 MHz CPU, you make the memory and CPU run at the same speed. That is preferred. If you have a CPU with a 100 MHz bus speed, there is usually an independent setting somewhere to make the memory run faster, at 133. Asus has those individual settings. I think that having your memory run at 133 MHz bus speed is where you will get the best bang as far as memory settings go. The next thing is to experiment with specific memory speed settings (not the same as bus speed) like the nanosecond rating and the CAS delays.

With nanoseconds, smaller is faster. Shorter time per cycle.

I have an Asus, not an Abit, so I can't give you explicit instructions for your BIOS. My mobo's BIOS settings have auto (SPD) and manual memory settings. I first used the auto to see what SPD set it to. It set it to 7.5 ns (nanoseconds) with the three different CAS settings at 2-3-3. CAS 2.5, like theBlackman said. I then experimented with manual settings and set it with 2-2-2 (each one is separately adjustable in my bios) and it worked fine during some benchmark tests, so I left it at 2-2-2 and never had a problem.

This is not to say you will not have a problem with such tinkering. The safe thing is to use the SPD auto setting and forget about it.

I have found that the symptoms of bad memory or too-fast manual settings is that that the computer just stops. I have not gotton data errors and kept running. I'm not saying that will never happen, only that it has not happened to me that I know of. If the computer stops, then on bootup go into the bios and readjust settings.

I don't have any settings on my motherboard for normal fast, turbo, or whatever. I don't know what those terms mean. Mabe your mobo manual can tell you.

25th Oct 2002, 22:04
Good Day Peter...thanks for the reply as always :) Regarding explaination of the settings for RAM...Normal, Fast, etc. no it does not explain their meanings as I have stated earlier in my posts :( That's why I can't get an understanding of what they mean by it and why I've tried to get some info from you guys if you might have an idea. This is one area the manual doesn't cover very well :(

As far as the RAM specs...Right on Crucial's site for this model...says 7.5ns CAS 2 :) I guess I'll have to send some emails or call to get the specifics I'm trying to find out ;) At least Abit has a "local" number, well actually local toll :D However, the info you and Varguard offered are helpful anyway to give me some additional thoughts to ponder :) Ta and Good Hunting!

26th Oct 2002, 01:54
Well if that don't beat all....I went into my BIOS again to recheck FSB on my CPU and I don't get it? My manual for CPU says it has 200FSB capability (even for my 950) and right now it's at 100/w 33PCI...there are other settings for CPU/PCI Clock speeds or a seperate selection for CPU FSB...but that's greyed out. I guess it would have to come under enabling "User Defined" to change things. I don't want to change the speed of the CPU just the FSB and as far as the PCI clock...even Powerstrip says my display adapter is PCI 66mhz capable? It just looks like to me I'm not getting the performance out of this system that I should be? My MB manual says it will support higher settings but only known ones at the time are defaulted in for alternate choices but was capable for higher as these things were developed to use.

I did change my RAM to "fast" and so far everything seems hunky dory :) I dunno, maybe I should just take the whole thing to a shop and let a pro set the darn thing up...I just don't know who to take it to and I don't want to take it to Fry's as an example...too busy and too expensive :D Besides also CompUSA screwed up one puter a long time ago too and had to replace some things...burned my MB as I recall :( I'd like to take it to a local shop but don't know anyone to get a recommend from :( Darn, darn darn! Between that ole rock and hard place again!

So guess that's my whole story for now and maybe next week I'll call Abit's Techs and see what they can tell me and guide me along the way to maybe seeing about some of these questions I have and maybe improving some things along the way...particularly now that I'm going to be putting a faster CPU in it as well now too :D Ta and Good Hunting!

26th Oct 2002, 06:45
Huntress, everything sounds like it is right.

The Duron runs at a FSB speed of 100Mhz, but is "double-pumped" for the 200Mhz FSB speed (like DDR-RAM). Athlons run at 133 (266) and the newest Athlons at 166 (333).

The FSB/PCI divider is also correct, as PCI slots run at 1/3 the FSB. If you raise the FSB, you also raise the PCI speed.

AGP slots (your display adapter) are essentially PCI slots that run at 66Mhz. AGP 1x = 66Mhz, 2x = 133Mhz, 4x = 266Mhz, 8x = 533Mhz.