FSB on a A64?

[wilsonian]

a bloke who i work with has just purchased an Athlon 64 3200 system (parts - built him self). now he says he's getting memory errors when trying to clock the CPU but here's the thing he's tried 235x8 and 250x7 - is it me or is he stupidly over clocking his system so the generic memory he has doesn't work?

i thought the CPU's ran at 200FSB, and even though he has DDR 400 memory wouldn't it be the CPU crahing out causing the errors rather than the memory?

[mike_w]

If it's only PC3200 memory, then I suspect that it doesn't like going 35mhz or 50mhz over its guaranteed speeds, especially since its generic.

It may also be the CPU, but I would expect it to be the memory.

[wilsonian]

hmm... my point is that he IS over clocking the system, am i correct?

oh and it's PC 4000 not DDR 400 - sorry

[Swafe]

i always thought it was 200 too, (ddr400) could be wrong tho

i know the fastest HTT is 1ghz, (200*5? 250*4?) not sure

[mike_w]

It might also be the motherboard - if the motherboard is only guaranteed to run at 200, then it might not be able to handle much higher. You should also consider the fact that generic RAM doesn't always work very well, so that may be the cause of the problem.

Try using Memtest86 to test for memory errors, first when not overclocked, then gradually increasing the overclock.

[wilsonian]

yeah though as much - i have recommended memtest etc - i just wanted to make sure he was over clocking it - he's one of these people than "knows what he's talking about" and is always right! LOL

[Platinum]

That looks to be a S754 mobo and chip, if thats the case that dont like going above 220MHz as the AGP and PCI bus's will crap out, thats prolly the prob.

A64 systems dont have a FSB btw...

[TiG]

That looks to be a S754 mobo and chip, if thats the case that dont like going above 220MHz as the AGP and PCI bus's will crap out, thats prolly the prob.

A64 systems dont have a FSB btw...

ERM what you mean A64 systems don't have a fsb??????. whats 220mhz you talk about above if its not FSB????. - Its link to memory is still run on the core frequency of the processor - even if its on chip which is still fsb. Saying amd64 systems don't have a FSB will confuse the hell out of people. Sure Hypertransport takes care fo the communication with the rest of the system, where the traditional term for FSB comes from but, the term has loosened over time, due to QDR from intel etc DDR memory abusing this term to 400mhz too. BUT imo a64 still has a CORE FSB, and from what everything else is pretty much defined..... Otherwise you couldn't get memory speeds from it either...

But thats another point......Anyway i'd say to your friend find something that does work, say standard 200mhz fsb and crank the thing up slowly, a few mhz at a time, 200 then 205 etc etc etc... Once he finds one that doesn't work, try that with .1v more and see if it works. and keep going.

He should soon be able to find the limits without a problem. One thing I will go with platinum on, and thats in my experience the FSB on AMD systems do not scale quite as high as P4 systems on the 754 socket. The 939 scores i'm seeing seem to suggest the opposite and i've seen some silly fsb speeds so far....

TiG

[BUFF]

The 939 scores i'm seeing seem to suggest the opposite and i've seen some silly fsb speeds so far....

400+?
I'm still trying to get my head around HTT v traditional fsb etc.
A lot to relearn for o/c when I move to AMD64.

[Firelord]

That looks to be a S754 mobo and chip, if thats the case that dont like going above 220MHz as the AGP and PCI bus's will crap out, thats prolly the prob.

A64 systems dont have a FSB btw...

Depends on board and manufacter. i have an MSI K8N and that has locks as does v1.1 and on KV8 Pros

[Mblaster]

Check this thread out at extremeoverclocking.com for info on A64's FSB (or lack of), they even got pictures explaining it

[Lee H]

Heres what the FSB of an AMD 64 is... or is not in this case

AMD Athlon 64 processors use AMD's HyperTransport to interface with the North & South bridges instead of through the old FSB and run at up to 800MHz DDR (or effective 1,600MHz) which gives a maximum of 6.4GB/s bandwidth. ( so there is NO FSB - instead its the hypertransport system )

The AMD Athlon 64 have an increased processor stage pipeline from 10 to 12-stages (Intel Pentium 4 has 20-stages). There are core architecture improvements making up for the slight loss of performance with the deeper pipeline. Having a small pipeline means that AMD processors can do more instructions per clock-for-clock than the Intel Pentium 4, but having such a deeper pipeline partly enables the Pentium 4 to run at higher speeds.

The following thread brought up a shedload of useful info and is worth a look ;

http://forums.hexus.net/showthread.p...8&page=1&pp=15

Hope this helps

Lee

[Swafe]

That looks to be a S754 mobo and chip, if thats the case that dont like going above 220MHz as the AGP and PCI bus's will crap out, thats prolly the prob.

A64 systems dont have a FSB btw...

well yes and no, it does technically have a FSB, as its the speed the CPU talks to the RAM, didnt AMD just rename it hypertransport tho ? to make it sound uber cool and make people want to buy it ?

think its like intel....i mean it has a FSB, but its not 800mhz is it..