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Old HX chipset based K6-2 400 slower than a P-Pro??

Posted: Sat Mar 22, 2003 4:16 pm
by Buzz
I have upgraded one old P120 box with an Asus T2P4 (Intel HX chipset) board in it.

I changed ths cpu to a AMD K6-2 400MHz and put 128MB RAM in it.
I'm using it for folding... and i also got a P-Pro200MHz with 190MB RAM folding too.
They are both using the text based folding proggie and are equally configured.
Both machines are also running Win2k Freshly installed and equally configured.

Problem is:
The P-Pro 200 machine is folding quicker than the K6-2 400!!! Not by much, but still: WTF???

Could this be because the HX chipset is unable to cache RAM beyond 64MB?
I read somewhere that u would get a performance decrease if u used more than 64MB in this board because it cant cache more than that, but i didn't think it would fall by this much!!

Can someone explain? :)

May be the Work Unit..

Posted: Sat Mar 22, 2003 4:23 pm
by eGoCeNTRoNiX
It's probably just the work unit.. They could each be doing a different one, and the times to process a frame can vary from machine to machine.. The 200 may just be folding a WU that's a little smaller or less complex than the 400.. Hope That Helps.. eGo

Posted: Sat Mar 22, 2003 4:51 pm
by DocSilly
I believe the HX chipset was the only one back in the days that could use 64MB+ BUT it required a so-called tag-RAM, a small additional memory chip, 32KB or so, to access the memory above 64MB.

Posted: Sat Mar 22, 2003 5:43 pm
by Buzz
eGoCeNTRoNiX, Thanx for the tip... i didn't think of taht.

DocSilly, you are absolutely correct. However, i don't have that TAG RAM on my mobo... it's a upgrade option. It's also a jumper on the mobo. Default is 64MB, but if u have the TAG RAM u set it over to 512MB. So until i get that TAG RAM my mobo is unable to cache more than 64MB.

Anyone know how much this actually affects performance?

Thanx :)

Posted: Sun Mar 23, 2003 12:16 am
by Slugbait
Not sure about the architecture for those old K6 procs, but I believe it followed the classic x86 route.

The P6 was designed specifically for NT, so you're getting superior cycle production just from that alone...if you were to install Win9x on the P6 box, you would see a sharp decline in performance, probably on par with the K6.

So perhaps you should nuke NT from the K6, and install Win9x...you might see a substantial increase in performance.

Posted: Sun Mar 23, 2003 12:42 am
by Judg3
Don't forget tho, the AMD has a 64kb cache that runs at half speed (50mhz) vs the Pentium Pro's cache side of anywhere from 256k to 1MB that runs at full speed. A PPro is basically a baby Xeon and shares a lot of the same characteristics of it. I don't know if Folding is like Distributed.Net's client, but if it is then cache speed and size makes a big diffrence

Posted: Sun Mar 23, 2003 5:32 am
by Buzz
Originally posted by Judg3
Don't forget tho, the AMD has a 64kb cache that runs at half speed (50mhz) vs the Pentium Pro's cache side of anywhere from 256k to 1MB that runs at full speed. A PPro is basically a baby Xeon and shares a lot of the same characteristics of it. I don't know if Folding is like Distributed.Net's client, but if it is then cache speed and size makes a big diffrence
Yes it is Distributed (http://www.foldingathome.com)'s client... text version.
I dunno either about the K6-2... but the P-Pro has 256Kb of full speed cache. :) It's a real beauty!! :)
+ cahce onboard...
The P-Pro is the mother of P2, P3 and the first Xeon's :)

Originally posted by Slugbait
Not sure about the architecture for those old K6 procs, but I believe it followed the classic x86 route.

The P6 was designed specifically for NT, so you're getting superior cycle production just from that alone...if you were to install Win9x on the P6 box, you would see a sharp decline in performance, probably on par with the K6.

So perhaps you should nuke NT from the K6, and install Win9x...you might see a substantial increase in performance.
That might be... i have two identical boxes (Asus T2P4 and K6-2) but gave one to my brother. Installed Win98 on that one and it seemed a lot more responsive....
Wanted the stability of Win2k... :( bwahaaa....

Posted: Sun Mar 23, 2003 11:50 pm
by Slugbait
Yeah, there were quite a few benchmarks done on the P6 when it first debuted, all of them said, "Don't spend the money if you ain't gonna run NT".

However, the stability is more important for some than performance. So if your primary concern for the K6 was stability, stick with NT. Heck, I have a debugger machine that's a P5/166 with 64 megs running 2K Pro, and haven't rebooted it more than three times in the last year...otherwise, it runs 24/7.

Posted: Mon Mar 24, 2003 2:13 am
by Buzz
Yeah... beginning to remember now :) still... werent expecting this.

I throwed in Win98 yesterday... menus and such are much faster now... gonna see how stable it'l be.

Thanx all.

PS: Still don't know how big performance hit i get becuz of the caching thingy... ;)