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Buffalo PC3700 and vcore problem

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xhoangx

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Mar 17, 2003
i just replaced my 1x512 pc3200 ram with 2x256 buffalo pc3700 bh-5 ram and i get no errors in memtest86 with stock vcore and 2.8vdimm but once i up my vcore i get errors at the last 2% of test 5 at any fsb. i had no problems in memtest86 with my old ram and high vcore, what could be the problem? are there any bios settings that can fix this? anybody else have this problem before? if i can't fix this problem, i'm stuck at only overclocking the memory. i'm at 5x211 right now just to be safe, i got into windows at 211x11 at stock vcore(1.5volts) but it freezes 5 minutes into doing anything, so i need more vcore to make it stable. by the way, i have a biostar m7ncd pro.
 
Well from what I hear BH-5 chips LOVE voltage. It could be that you need more voltage or that you just got unlucky and it won't go up much more. However at 211 it should be stable. What are your timings?
 
im at 2-2-2-5 stable at 2.8vdimm and 1.5vcore memtest stable, but as soon as i up the vcore any, i get errors in memtest
 
xhoangx said:
im at 2-2-2-5 stable at 2.8vdimm and 1.5vcore memtest stable, but as soon as i up the vcore any, i get errors in memtest

Well without more voltage (or maybe its just maxed) you probably wont be able to get much higher with those timings... usualy when people get really good resuslts with BH-5 memory people do volt mods and run upwards of 3v (3.2 even!).

Here is a lil' linky to seme voltmod instuructions if you are intrested http://www.motherboardfaqs.com/article.php?15.255

According to Buffalo http://www.buffalotech.com/memory/prod-ddrdimm.html its only gurenteed at cas 3 and probably 2-2-6 or 3-3-6 for the rest... But I bet if you tweak the timings a lil you can get it pretty high:D (don;t rule out other parts of your PC either, at higher FSB's it could be your motherboard or PSU that becomes the limiter).
 
it's not the fsb that i am worried about, it's the fact that i can't raise my vcore without getting memory errors in memtest86. i'm pretty limited to a low overclock if all i can do is 1.5vcore to be stable.
 
Hi, have you ever figured out this problem? I run into it as well when I boost my vcore on my xp2000 from 1.75 to 1.775, memtest errors all over on test5 but if i leave it at 1.75v no errors, but then I cant run prime95. Bump up the vcore and I can prime fine but of course that means I am failing memtest. Any Ideas???

Abit NF7-S rev.2
AMD XP2000 ([email protected]) volcano 11 +
2x256mb ddr400 11-3-3-2 @2.6v (no difference at 2.9v)
2x 80m intakes, 1x 120m side intake, 1x 80m exhaust
generic 400w PSU
idle 42 load 47
 
Sorry, I missed the whole thing about vcore lol, I msut have been tired or somthing :/

What are your temps, and PSU, and the REPORTED vcore and core voltages (use somthing like MBM)?

I would GUESS that its the PSU since for Zyl it is either one or the other that passes it's test.
 
I'm guessing it has more to do with the fact that you now have two dimms rather than which ones they are. But it is just guessing from here.
 
This sounds like it could be a power issue. What are your voltages (under idle and load)? What PSU do you have? If you take out one stick does it go away? Whatif you disconnect everything unnecessary from power?
 
Gnufsh said:
This sounds like it could be a power issue. What are your voltages (under idle and load)? What PSU do you have? If you take out one stick does it go away? Whatif you disconnect everything unnecessary from power?

My PSU is a generic 400watter that came with my case, my rails seem within tolerances, 5v=4.97v, 3.3v=3.19v(fluctuates 3.2-3.17), 12v=11.88v. At 1.75v memtest passes with flying colors but prime95 fails cuz vcore fluctuates between 1.73-1.71v (its set to 1.75v in bios but NF7-s undervolts? by .25v) but at higher vcore memtest fails. So the PSU is what you guys think is wrong with my system? Readings were taken using MBM5 and speedfan.

P.S. this is when I am trying to go 200x11 or higher, 200x10.5 is stable as a rock in sig below.

Abit NF7-s Rev.2 1.7bios
AMD XP2000 JIUHB 0320 ([email protected])
2x256mb ddr400 DC 11-3-3-2 @2.6v (2.9v no difference)
9500np softmodded 350/300
Volcano 11 + (42idle 47load 28ambient)
2x 80m intakes, 1x 120m side intake, 1x 80m exhaust
generic 400w PSU
 
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What I would think of is, your psu probably can't handle all the voltage requsted so the mem get's undervolted, or you mobo is undervolting th vdimm.

use a multitester to check the voltage during load when your vcore is high, and check stock as well, that's my opinion.

Suma.
 
Cooling your mosfets might help.. I think anyways. They should provide more stable power, it has been shown to lower reported (and maybe actual) CPU temps too, those mosfets really heat up the motherboard!
 
So do I (Sparkle made), anyway try what CrashOveride told you, it might help.

I also said: "or you mobo is undervolting the vdimm". try a friend's mobo.

But first, I would check the mosfets, like CrashOveride said.

Suma.
 
I have the Buffalo chips as well and they would max around 226Mhz at 2-2-2-6 at 2.85vdimm. These chips LOVE voltage i now have 3.2vdimm with the vmod and they are happy.

It does sound like you are having voltage issues. I suspect the PSU not keeping your rails stable. Like it was stated before, the Buffalo are rated at CAS3 but i have yet to get mine to boot in anything other then CAS2/2.5 go figure.

I have not tested these sticks with Memtest86 but i can tell as i have pushed my FSB with my Buffalo ram that they are having errors because my loading times have diminished as the FSB has reached near 290. It is possible that i could have other issues since i have all stock cooling STILL!
 
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