Overclocking with corsair 2gb xms 4000pt - Help!

With my 1GB of samsung DDR memory i had my AMD 64 +3000 running at 2.37GHZ (262*9) HT was on 4x and memory set to ddr333.

I recently bought Corsair 2GB DDR XMS4000PT TwinX Memory and want to overclock my processor again but when i try to my system either doesnt boot or gives me errors. I'm not a pro at overclocking so if somebody could point me in the right direction please.

What speed should i have the memory running at, its ddr500 so should i have it running at that speed or lower it when overclocking?

My motherboard:
ABIT Fatal1ty AN8 SKT 939 NVIDIA® nForce4 Ultra M/B

Memory:
Corsair 2GB DDR XMS4000PT TwinX

CPU:
AMD 64 +3000 - default speed of 1.81ghz at 200mhz

 

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You know most already but set HTT at 3 not 4, no benefits from 4 and possible troublemaker.

If chipset voltage is 1.5 increase to 1.6 - might not be needed but 1.6 is not too much.

Are you using latest bios 20? "Enhanced compatibility with certain memories." might be interesting.

Read up on Abit http://forum.abit-usa.com/forumdisplay.php?f=73 search those memory modules. Are they among those motherboard now works better with?

I have same Corsair ram and it sure has a special "feature". Find out more on Corsair forums. They often say 2.8v is the way to go if any problems. Well this ram can only work with 2.6v not 2.5v or 2.7+v. Do that and you get Memtest86 errors, lots. Has not stopped them from keep saying 2.8v but I think Ive read they are now testing 2.6 They make many versions with same model name so we dont have to share chip or that 2.6 demand - you can look it up here http://www.houseofhelp.com/forums/showthread.php?t=44365 Anyway, until Memtest86 say otherwize use 2.6v - even a bit of over/undervolting from motherboard could be important here. See Abit forum about that. When I figured that out ram is ok up to 262fsb. Ive tested with Prime95 (Blend) and of course Memtest86, for 12-15 hours. Prime95 failed after 4-5 hours until I increased chipset voltage from 1.5 to 1.55, why I mentioned it before. Crazy and picky test but nice when it does not fail! Some have gotten more impressive numbers but ok for "cheap" ram. Dont change timings from 3-4-4-8 unless you run 200fsb or close to. I can use 1T so at least ram can be ok with that, hopefully goes for memory controller as well. I couldnt run 1T with 2 different sets of low latency ram but these much slower ones have no problem. May be a bios issue.

Even if NF4 runs great with ram at lower speeds I think you will get a little extra (benchmark)speed when 1:1 and so 4000PT should fit perfectly if they perform like mine - and you cant get more out of cpu. Do a quicktest with SuperPI but dont cry if they only work at max 250 and you really want 270. Just lower them to whatever works. If you can use 2.5-3-3 at 200fsb that might be just as good if not better in games - but be sure you test before loading OS and take advantage of those 2 forums - what does other people use? Memory not really a major factor, cpu mhz is more important.

My bios misread modules btw, timings are wrong - CAS is 2.5. Wont work for long with these 4000PT. Could also be your problem. Set them up manually, including the very important voltage. Memtest86 will instantly show errors in test 5 if they only work with 2.6 and you give 2.75, +- 0.05v is allowed range here! Possible you have version/revison which actually benefits from more voltage, test away and find out.

 

Thankyou very much for your help! I've updated my bios as you said and do a bit of reading up

I've decided to get new ram after of this has it wouldnt boot up when i dropped memory down to 466

Thankyou very much though i'll use your advice when i get my new ram!