AMD nForce2 FSB problem

[Mental]

When I try to overclock my nForce2 chipsets FSB to more than 220MHz my computer becomes unstable and randomly shows bluescreens and reboots.

The chipset needs 1.8V to be able to run at 220-225MHz. I am able to set the FSB to 231MHz with 2.0V but the system becomes really unstable.

Could this be because of a limited PSU? My PSU is an Enermax whisper-series 430W.

My CPU is an XP-M 2600+ 45W. Even at 1.45V and 45W CPU the computer is extremly unstable at higher FSB than 220MHz.

[saaya]

welcome to XtremeSystems :toast: :)


hmmm you could try the L12 mod

what board? it could as well be your board having reached its limit already. better nb cooling and higher rails could give you a boost, but some nf2 boards just dont go above 230.

are you sure your memory is not limiting you?
have you tried more volts on your cpu as well?
what are you running your cpu at? multi fsb vcore cooling
what is your cpu cooling? temps in idle and load?
what is your nb cooling?
mosfets cooled?
sb cooling?

what psu?
what are the rails at in idle and under load?


please get used to posting all infos you can give us when you need help, thx ;)

[reject]

^^^what he said ;)

[Mental]

Ok, tnx... I'll try to specify more closely....

CPU:
AMD Barton XP-M 2600+ @2200MHz@220FSBx10 @ 1.45V - 28C idle & 31C load
or usually:
AMD Barton XP-M 2600+ @2640MHz@220FSBx12 @ 1.80V - 45C idle & 50C load
OCZ PC4400 Gold E.L. 2x512MB matched DualCH 8-4-4-2.5 Ram @ (5-3-3-2.5@440MHz)
EPoX EP-8RDA+ V2.1 mainboard Socket A nForce2 Ultra400/MCP-T
POV GeForce4 Ti4200 @ 285/705 with a passive Zalman Heatpipe cooling and no voltmod.

Enermax 430W PSU
1xWesternDigital 200GB HD
3xMaxtor DiamondMax9 200GB
1xMaxtor DM9 120GB

1xDVD-rom
1xCD-burner

Cooling:
MIST tsunami watercooling set dualradiator (http://www.microplex.no/rubweb/varer.asp?ARTNR=MISTWCKIT04) This is just a modified AquaComputer set. Currently I'm just watercooling the CPU, cause my GF6800GT went to Kahoonas when I tried to mount the AquaComputer waterblock. And the radiator is just using 1fan because I didn't have tools to create another 120mm fan hole in the top of the casing.

My NB is cooled by a passive Zalman (http://www.microplex.no/rubweb/varer.asp?ARTNR=ZMNB47J). I heard that watercooling the NB isn't smart because it heats the water and therefore reduces the coolingability on the CPU and GPU. Though I'm considering buying another singlefan 120mm radiator and a northbridgeblock when I get my new GF6800ultra.

hmm....

NB temp @ 231FSB & 2.0V 41C LOAD
@220FSB & 1.8V : 37C

[funkflix]

----- ;)

[saaya]

how much vdimm?

nb watercooling IS a waste, but get a better thing than the zalman. get a copper 60mm heatsink from an old socket a, there are good cheap heatsinks like that in sale outs or on ebay.

and try the L12 mod :)

and can you get higher with just one stick?

[funkflix]

I'm really sure the 2 x 512MB Doublesided hold him back! ;)

[Mental]

Tnx!

I think I'll try the L12. My waterpump just got broken :( have to go back to my old aircooling for the moment :(

Do you think I would get higher FSB with just one dimm? The RAM is specified to do 550MHz DDR so it souldn't hold me back, unless dualchannel or having two dimms is a heavy load on the NB. I before I bought the OCZ, I had a TwinMOS winbond 512MB. I could only do 220MHz then too... I'll try with 1xOCZ though...


Edit:
It seems the NB temp dropped 10C with the L12mod. Amasing! Seems like I can boot windows at FSB speeds I couldn't even see the BIOS boot screen at before... Haven't had time to do any stability tests though the system appears stabile at currently tested 235FSB with both dimms ;)

[funkflix]

I'm sure, try it with one stick!

I have 1 x 512MB BH5 and can go up to 265MHz, with two Sticks (have bought
an other this week), i cant go up to 240MHz stable, doesn't matter how much
Volts i give.(3,6V) Thats the Proble with nforce2 and 2 x 512MB!

:)

[jjcom]

yeah if you water cool you basicly must get a different heatsink on the NB if its passive....and well..maybe you could help me out here too...KT600 ASUS A7V600-X
Processor:Athlon XP 2700 (T-bred, unlock multi)
RAM: 1x OCZ 3200 2-3-2-5

Alright i can't do 400mhz FSB....very well..that meaning I can't restart the comp at 400mhz FSB. Its not because of RAM...was running it 333. Anyone know why? I can run stable but not I can't restart the comp. I'm using the stock ASUS passive heatsink...my guess that it might be this....according to my case's thermal probe the heat sink has gone up to ~120 degrees F.

[Mental]

Seems 2xdimms works just as fine as 1xdimm. I can boot windows at 240FSB with both. Highest stabile clock before L12 was 220FSB. I seem to get A LOT of bluescreens though whatever FSB.

This might be because I tried to boot windows when my waterpump failed and the CPU might be damaged. It could also be the L12 bridge... I don't know...

Could the CPU be heatdamaged despite that I can boot the computer? I don't really have any experience in burning CPUs :S

I think the NB-heatsink I use works fine, since I get NB-temp @ 33C with 2.0V shouldn't be a problem. I think I'll follow your advise and glue the Copper-socket-A-heatsink I'm currently using on my CPU to the NB when I get a new waterpump. VDimm is at 2.9V (max in my unmodded bios).

[HydroX]

err, my Shuttle AN35N Ultra can reach 230 MHz, with standart Vdd ( 1.7V ) using AMD Sempron and ... PC2700 memory ( double sided ).

the voltage
Vcore ~ 1.65V
Vdd ~ 1.7V
Vdimm ~ 2.7V
Vagp ~ 1.5V

using CM X-Dream SE with Vantec Tornado
http://img54.exs.cx/img54/127/228_33310.png

[funkflix]

I can reach 270MHz with Doublesided, but not with two Sticks :rolleyes:

@ Mental

U have tried the Bios, i had postet? Give me at least + 15 MHz at FSB !

http://people.freenet.de/funkflix/267fsb.jpg

[Mental]

Hey, GravDiggA

I didn't try your bios. My board isn't an Abit NF7 its an Epox. Does that matter? Does any Bios for the same Chipset work? I need a bios which can give me more than 2.0V for the vdd.

Seams my bluescreens appeard because of the CPU and my bad air-heatsink. The CPU LOAD temp is more than 60C @ 1.65V (runs fine @ 2.2GHz @1.45V @ 45C I can live with that till I get a new waterpump).

[funkflix]

Ups, im blind :D I thought u have an NF7.. No , dont flash that Bios then,
or ur Board is some rubbish ;)

I will delete the Links, its better.

Don't think the Vdd is holding u back! I have only 1,8V on my Abit ;)

[Mental]

My board can only do 235FSB with L12 @ 2.0vdd. Once I set it to 239FSB through 8rdavcore, the computer hangs. Anyone with an EPox 8RDA+ v2.x modified bios?

[di_entropy]

im also using 2x512 dimms and i was stuck at 213fsb on my nf7 even with 3.2v vdimm

i remembered reading somewhere that for 2x512dimms CPC off bios is sometimes necessary with high FSB so i disabled CPC and now running 230fsb stable..

give CPC off bios a try.. you lose some performance at same speeds but if you can get higher fsb it makes up for it :)

[Mental]

Well... I can now do 236FSB without CPC off, with the L12mod, 2.0vdd and 2xdoublesided OCZ gold.ed. lh. PC4400 512MB's.

Well... for my Epox 8RDA+ v2.1 board, there is currently no cpc-off modded bios. At least not one that I am able to find...

Because of this I though I would look into bios-decompiling and reprogramming... I was able to decompress the newest bios 8rda4729 (http://www.epox.com.tw/eng/download.php?t=U0wyRnpjMlYwY3k4eU1EQTBMekE0THpNd0w ySnBiM016T0Rjek1qVTVNREV5TG5wcGNEMDlQVGh5WkdFME56S TVD) I found the adress of the chipsets registry. If I get some more time to work on this I could be able to change the bios into an CPC disabled version. I also found the place where the voltage-settings is stored, though I guess the voltage regualtion is done by onboard-transistors and the bios is just choosing which voltage-circuit to use. Maybe it is possible to get the system to use two circuits, 1.6+1.8V?? Depending on the board configuration you would get 1.7v or 3.4v...

Though I do not get any FSB boost by using just one memorystick and guess that the use of two sticks is not a holdback. The fact that my memorysticks is doublesided might be though. Unfortunately I do not have any way of testing this without any singlesided modules.

Anyone with experience in using single- vs doublesided ram?

[computer_geek]

i am using D26 spit-fire rev2

nf7-s r2 with all vmods

cpc on

ii can go 500 but ram cant keep up