AMD CPU Problems

Message from user:


I have well over a dozen end-users who are complaining about slow performance, all with Athlon 700 (OEM). It seem rather unusual to have such a high complaint rate, particulary only with this speed processor. First
of all, are their any recalls that I as an AMD reseller should be made aware of?

I have tried to troubleshoot the various problems as much as possible, but cannot find the cause of the problem. Replacing 700mhz with a 650mhz or 750mhz **Dramatically** increases perceived speed. Here is a breakdown of products used:

Mainboard: Epox, FIC, MSI, Biostar & Gigabyte
Memory: PC-100 or PC-133 SDRAM (Grade A+) Mosel, MicronTech, Infineon
Bios: Latest available
Operating System: Windows 98 Second Edition
Power Supply: 300w or better, generally In-Win
Hard Drive - Western Digital ATA/66 with 80-conductor cable & ATA/66 enabled disabling does not help)
Video Card - AGP & PCI, many brands (ATI, 3Dfx)

Any/all suggestions you can provide would be greatly appreciated. I am having to pay for replacement processors out of pocket, since OEM's are not returnable.

Quote:

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Originally posted by WinDrivers:
Message from user:


I have well over a dozen end-users who are complaining about slow performance, all with Athlon 700 (OEM). It seem rather unusual to have such a high complaint rate, particulary only with this speed processor. First
of all, are their any recalls that I as an AMD reseller should be made aware of?

I have tried to troubleshoot the various problems as much as possible, but cannot find the cause of the problem. Replacing 700mhz with a 650mhz or 750mhz **Dramatically** increases perceived speed. Here is a breakdown of products used:

Mainboard: Epox, FIC, MSI, Biostar & Gigabyte
Memory: PC-100 or PC-133 SDRAM (Grade A+) Mosel, MicronTech, Infineon
Bios: Latest available
Operating System: Windows 98 Second Edition
Power Supply: 300w or better, generally In-Win
Hard Drive - Western Digital ATA/66 with 80-conductor cable & ATA/66 enabled disabling does not help)
Video Card - AGP & PCI, many brands (ATI, 3Dfx)

Any/all suggestions you can provide would be greatly appreciated. I am having to pay for replacement processors out of pocket, since OEM's are not returnable.

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Well, with all the different configurations used I will have to agree that there is something wrong with the chip. We did not use OEM chips for the longest time, because of the fact that you are stuck with them. After a while we found a supplier that that will give us one year warranty on OEM chips, which helps, but we only use them when there are no retail boxed chips available.

I don't really have a good suggestion on your chips, this is kind of a sticky situation. The one thing I would check is to see that these chips are actually what they claim to be and not counterfeit(relabled) or altered chips. I would assume you could get all the ID info from AMD.

I know at this point I am preaching to the choir, but I would not buy anymore oem chips. I don't know about your suppliers but the ones I deal with, there is only about a $20 difference between OEM and retail, and after you buy a fan, the numbers and the irritation do not add up.



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Bill Gates? I never heard of him. Is he famous or something?

I agree, you may have a re-marked chip, i dont remember any web sites that describe how to tell, but you can check with ones like slota.com or with AMD directly to check.
also - might want to check to see if the cache is running at the correct value, it could be set wrong, causing slower performance (dont remember the value...)
try getting a couple of chips retail boxed - and test it then.
also note that percieved speed isnt accurate, run some bench scores (3dmark2k from madonion.com or sisoft sandra.
hope this helps

kannibul
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[This message has been edited by kannibul (edited July 10, 2000).]

I work in a computer store in Sunnyvale, Ca. Our clientele is mostly IT pros and
hobbyists who know their stuff. I have built several of these 700 MHz Athlon systems
using ASUS's K7M Motherboard, Crucial Technology RAM and OEM CPU's. The
other components vary, we've had problems with some video cards and Winmodems.
(If I ever get my hands on the guy that dreamed up Winmodems....) but not with the
CPU's. Windows 98 and 98SE are glichy with random freezes that we have not tracked
down but WinNT 4.0 runs stable and faster. It almost seems that 98 can't run fast enough
to keep up. As long as the user stays away from Win95/98/98SE we get zero complaints
and some of the fastest benchmarks we've ever seen.

With that background I'd say try an alternate OS like NT, Linux, BE, etc. I bet you'll see
the problems vanish.

These performance errors... Can you be more specific? The benchmark #s would also be helpful, and since this is win98, you might also take a look at the system monitor, to see where the bottleneck is taking place.
Is this in an application, during boot??? Might try safe mode to see if there's a driver loading that's screwing up the IRQs, safe mode and/or step-by-step confirmation in the boot process might help to isolate that. More detail would be great here, that would certainly give me more of a handle on this problem, and perhaps break it loose for you.

here is your answer.
starting from 700 and up the cache speed on these chips is something like one third the chip speed.
650 and below has like a 1/2 the processor speed cache speed.
i may not have explained it right in a technical sense but basically it is a known fact that the higher up you go in chip speed with the athlons, the slower the cache speed will be.
this is why amd cleverly released the thunderbird which starts at 700mhz.
it has half the amount of memory but runs much faster then the athlons memory.

regards

I have a win2000 machine with a k7-700 (oem) chip and 256 megs crucial pc100ram and it often feels as if my 98se machine with a k7-550 (retail) with 128 crucial pc 100 ram is as fast or faster!!! what gives is it just me or is there something cus both machines have basicly the same config diference being one has a dvd and cdrw drive and a voodoo3 3500 the other only has a dvd drive and a voodoo3 3000.

I have seen this problem up to a point. The first thing is... These procesors run WAY too hot. The second, The motherboard doesn't warn you about this. It may list a temperature but it doesn't seem to jibe. I have found that with the 700's you must use a 300 watt power supply (more powerful fan) and an extra case fan to push sufficient air flow. Also use the largest cpu fan you can get. Finally, ignore the heatsink contact pad (scrape it off) and use real heat sink grease. It appears that the processor is developing hot spots and then slowing down. I find that with conventional 250 watt power supplies a great deal of hot air builds up around the processor even with the case off.
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[QUOTE]Originally posted by WinDrivers:
[B]Message from user:


I have well over a dozen end-users who are complaining about slow performance, all with Athlon 700 (OEM). It seem rather unusual to have such a high complaint rate, particulary only with this speed processor

Digsy76, You're right!
AMD experienced big problems with cashe memory suppliers, so they had to reduce cashe speed down to 1/3 CPU speed. Also was big problem connected with using high-speed cashe memory in SlotA.It's well-known fact. Now this problem solved in new CPUs.

seems to me I remember an article about the early athlons in that speed range having an early and a late version..something about backside cache..I'll try to locate it. By the way, does your bios or any system info program like norton utilities or si-soft sandra see anything as far as chip id?

I built my own system, asus k7m, micron pc133 ram, K7-700, Gefouce 256 sdr, Wd ata/66. And it rocks! I love my system. Runs very fast. I also have an alpha p7-125 cooler, 1 intake fan and a 5 1/4' drive bay fan. Runs cool and Fast. I can even adjust my Fsb 105. I also have some friends who have k7-700's with epox mob and theirs rocks as well. I think you got some remarks.

Something I noted a few months back -- while using WhatCPUIs? software to check the clock speed of processors, the AMD Athlons were 15 to 20 Mhz UNDER the stated performance speeds.

For instance, the 700 Mhz Athons were running a "WhaCPUIs" benchmark of 685 Mhz. This was pretty consistant, with none of the AMDs reaching the advertized or expected speed. The Intel chips worked within +/- 1 Mhz of the expected speed.

I've wondered if this is part of the old "P-rating" deal from years back.

Craig.

You may want to check the motherboard bios...some have settings to throttle the cpu down if it gets too hot. Also, check your cooling, get the latest bios.

Digsy76 is correct in pointing out difference in cache speed, however the break-point is actually 750mhz. Here is the breakdown: K7-500s to 700s use a 1/2 clock divider for cache speed (i.e. 700s have 350mhz cache--the highest speed cache of all non-Thunderbird/Duron Athlons). From 700mhz to 850hz, Athlons use a 2/5 divider (i.e. a 750 has 300mhz cache). 900mhz to 1ghz use a 1/3 divider. Note: this does not apply to Thunderbird or Duron parts, all of which use full-speed on-die cache.
Ribbon Cable:
I have not used WhatCPUIs but most utilities that report cpu mhz cannot actually read the speed from the chip, they simply tell the processor to perform a specific operation/set of operations and time it, then report a estimate. Most of these programs are also written around Intel timing sequences, which means they are more accurate at determining Intel mhz than AMD. Since clock speed is actually determined by bus speed x multiplier (supported in .5 increments), and Athlons do not use the PR system, Athlon mhz will be in 50mhz increments.

Heh, I know that was a long post. Hope I didn't put anyone to sleep...
Hope some of my techno-babble helps you out.
https://forums.windrivers.com/images.../2000/04/1.gif

Yeah Toast, you are right about the divisor breakpoints.

For good cpu/chipset/agp/other info I use WUCPU www.h-oda.com
It tells you the cache divisors and other stuff like what AGP speed you're at currently. It supports most new chipsets and cpus.
--Fil