Good overclock, unsure of next move..

Alchemist

Hi, this is my first post here. I've had my machine for over 2years now, and am waiting for the Phenom processors to become cost effective (and for AMD to do a few core revisions!), so I am about to upgrade my Sempron 3100 to Athlon 3400 (mobile, 1mb cache, unlocked multiplier) to give my machine a new lease of life. I currently run a Sempron 3100 (will post my specs below) and I have over clocked it nicely to 2610 (stock=1836); however I would like a) comments and b) some clarification on terms I do not understand.
Anyway, lets cut to the chase;
cpu:Sempron 3100 (socket 754)
memory: 2x1Gb (ddr400,3200) running at 166 (2.5,3,3,7) brand unknown
mobo: Abit KV8Pro 3rd-eye (bios: rev. 26)
cooling: air AMD stock
now for some numbers:
LDT=x5
FSB=200
DRAM=166 (2.5,3,3,7)
External Clock=290
Multiplier=x9 (fixed)
temp@idle=30C, temp@load=60C(sometimes a little warmer)
voltages: vcore=1.625, agp=1.65, ddr=2.7 (all else is stock)
pci:agp=locked
My system is stable-ish (though prime95 does fail; windows and games are all rock solid. I think I need to slacken the memory timings..)
so, following the overclock guide for AMD754, I am now confused..

1) Why is my FSB set to 200 when my external clock is 290? I thought they were the same thing? My HTT should therefore be 290x5x2=2900 which is WAY too high (according to the overclock guide for AMD754); is my FSB fixed at 200? if so, what is the point of lowering the LDT multiplier?
2) what is the HT link if it is not the HTT, and how is mine at 1161?

I could probably go higher if I lowered the memory to 133, but she's already warm enough at load!
So.. there you have my overclock which I think it pretty good for a Sempron. I am looking forward to the new cpu which should be arriving tomorrow, and then I'll be trying to squeeze all I can out of that- as it is a mobile cpu it is rated by AMD for up to 95C!!! so should be able to run her a little warmer than my old Sempron I also have a new copper heatsink..
Anyway, I ramble..
Alchemist

lemonlime

Hi Alchemist,

Welcome to Icrontic!

Couple of comments: Firstly, where are you seeing a fixed FSB value? In the bios? You are correct, there are numerous terms for this frequency--reference clock, base HTT, HTT, External clock etc. They are all the same thing. With 754/939 boards, it is not possible to increase the reference clock and maintain a default HTT frequency--you need to lower the LDT/HTT multiplier manually as you mentioned.

Secondly, be careful with the vcore. 1.6+V is high for a 90nm A64. Increasing it more will likely not benefit your overclock. Also, if Prime95 is failing, try to loosen up the RAM timings or using the 133 divider--that may do the trick. You may get some more out of the chip too! 290MHz reference clock is approaching the limits of what most 754 boards will do, unfortunately. 2.6GHz out of a Sempron is a nice OC indeed!

Good luck with your mobile chip. Be sure to let us know how it overclocks

Alchemist

Hi Lemonline
Thanks for the greeting!
yes, the values I quoted are in the bios; the FSB=200 is showing in the dram settings; however in uGuru I am able to set the External clock to 290. This is what is confusing me, if they are the same thing, why are they reporting differently? and surely if the FSB was 290, then my HTT would 2900, which should surely leave me smoking..
I would take a picy, but my wife has the digicam at the moment, and by the time she gets back I'll have the new cpu anyway (which should be today)..
I'll let you know how the new mobile athlon goes once I work out a stable OC.. I just don't want to break it my misunderstanding/misreading the terms on my mobo..
cheers again
Alchemsit

lemonlime

Ah, so you are using uGuru to chance the reference clock. This is a software based tool, correct?

If so, the BIOS is probably left at the default and your reference clock of 290MHz is not applied until you reach Windows. The software overclocking tool does not save its settings to the BIOS, which is why you see a different value there. Is there any value in the BIOS listed as 290MHz? You may want to try to overclock exclusively from the BIOS--you'll get more predictable results from there. Be sure that you either disable uGuru or remove it, or it will likely 'undo' whatever you set in the BIOS.

Have you been adjusting the LDT multiplier (HTT multi) from either the BIOS or from uGuru?

Best of luck with the mobile chip!

Alchemist

Hi
No, I am using just the BIOS which is also called uGuru; there is a software tool that does the same thing, but that is rubbish in my opinion; crashes and such far too easily.
I have adjusted the LDT from the BIOS, and it has had no effect.
I have also lowered the memory timings tonight, and they have had no effect on stability; though a slightly better score at P95 benchmark..
My new processor arrived today; I plugged it in and got POST errors straight away- the mobo has a LED number clock which shows the POST process and it got stuck at C3, which in my manual is "expand compressed BIOS code to DRAM". I did everything I could- reset the BIOS, unplugged memory (2x1Gb) and tried them both singly in both slots, unplugged the gpu, etc.. anyway, would not POST; same error; replaced my old cpu, and it's fine, back up and running. so my hardware is ok, but the cpu failed at the 3rd POST instruction- gutted
am talking to ebayer to get replaced (I hope); Abit site says it should be fine to run; my mobo should run the Clawhammer which is at higher clocks that the mobile processor I bought..
So, any more ideas on the FBS/External clock issue bizzare i think..
whilst you are here, any thoughts on why that processor would not POST? must be a duff cpu in my opinion..
anyway, thanks for your input, speak again soon
Alchemist

Alchemist

Hi again
well.. the guy has come back to me with the option of an Athlon64 Clawhammer 3400 1Mb cache, core rev CG.
sounds like a good deal, i think..
how do they overclock?
Thanks for your help
Alchemist

mmonnin

By lowering your RAM timings did you make those numbers higher or lower? Loosening RAM timings makes them a higher number usually decreasing benchmark scores.

Alchemist

Hi, I lowered the ratio to 133, but set the numbers to 2,2,2,6
should I lower the ratio, but keep the numbers, say, at 2.5,3,3,7 ?
Cheers mmonnin
Alchemist