ATI 4850/4870 voltmod thread

[jason4207]

in hardwareluxx we have tested the vmod with a 25k variable resistor, but 25k is to big its not accurate enough, i think 10k is the best choice.

is the vmem mod still working ?

If 25k isn't accurate enough then you want a higher value resistor...not a lower one.

I'm installing the mods as I type this. I'll report back w/ my findings.

[jason4207]

so for vgddr measuring point, one of those yellow points to ground? and for vgddr mod, two whitish points to 100k vr?

Yes & yes, but it's actually green and cyan. You might want to adjust your monitor.

I'll be able to double confirm that shortly once I finish doing the mods tonight.

[Boogerlad]

Yes & yes, but it's actually green and cyan. You might want to adjust your monitor.

I'll be able to double confirm that shortly once I finish doing the mods tonight.

to tell you the truth, i'm slightly colour blind =( sorry if i give out wrong colours of stuff. Thanks for clearing up the stuff about vgddr.

[jason4207]

to tell you the truth, i'm slightly colour blind =( sorry if i give out wrong colours of stuff. Thanks for clearing up the stuff about vgddr.

Well in that case I humbly apologize!

Good news! My mods work!



It looks like even w/ the VR maxed out at 100K the vMem mod starts out at 2.09v. That's quite a bit higher than stock. Maybe a higher value should be used...

2.09v is safe, though, and I made my mods easily removable, so it's all good!


Pics will follow soon.




****************************************

Pics as promised!

[Boogerlad]

Thanks! it's really neat!

[DemonEyez]

ok i see one card has the clocks higher but the other wont show.. winflash says the bios is loaded already.. do i need to disable ccc or mom ?

this is the active card the other inactive shows clocks corectly. 725 1125 in gpuz

I noticed your flash command:
-f - p 1 and -f -p 2

It's my understanding that the first graphics-device has device ID 0 and not 1, and the second graphic-device has device ID 1 and not 2

so the flash lines should be:

-f -p 0 for card number 1, with device ID 0
-f -p 1 for card number 2, with device ID 1

What happened is that with your first command you flashed the second card and with the second command flashed no card at all. Could explain why one of your card has higher clocks and the other does not

[darkskypoet]

I was curious about that myself.. But i noticed the -f, and I never used the -f when i did mine, so i wasn't sureif it was related to that or not... But My single card was "atiflash -p 0 filename.bin" ... And so the 1 and 2 looked off.

[gurusan]

I think -f just forces the flash regardless of device id and regardless of anything really.

[jimmyz]

ok i see one card has the clocks higher but the other wont show.. winflash says the bios is loaded already.. do i need to disable ccc or mom ?

this is the active card the other inactive shows clocks corectly. 725 1125 in gpuz

OK I just noticed the same situation, one of my cards was showing 625 after a reboot, I ran a bench (05) and when I exited I opened GPU-Z and both now show 900 /1100. try that to confirm, and please report back. If yurs stays like that open the current Bios with RBE and take a screenshot of the clocks tab.

[DemonEyez]

I think -f just forces the flash regardless of device id and regardless of anything really.

Correct, I use the 'f' parameter mainly for biosses that differ from the manufacturer. For example to force flash a Asus bios in a MSI card, vice versa and so on...

[rym]

bothcrads have acelero cooler 1.rv2
I have both cards running 775/1150 one at 1.26v and other 1.29v.
No volt mod on ram for both cards.
The one with 1.26 /pencilmod ran an hour under ut3 bot match great. I enter god mode and playdead and watch the screen with 31 bots. Ut3 is a great tester.
The other with 1.29v var/resister full 100k. needs to be tested better.. I played ut3 on the net for about 15 20 mins ..
want to see if it will run at these speeds @ 1.26v
Ram sinks get very very hot.
I want to find the sweet spot volt/oc/heat to throw on non variable resisiters hardmodded for duration of next year or so.
I think these gpu's like voltage .

Thanks demoneyes for your help here.

[Clemmaster]

Pencil mod done for Vmem, It now reads 2.108v, let's see how far it can run now

[gurusan]

Pencil mod done for Vmem, It now reads 2.108v, let's see how far it can run now

What is the vmem pencil mod? Please show me

[darkskypoet]

I'll second that with a Pretty Please

[Clemmaster]

In the Vmem area of course

My memory can't go over 1130 :/ I'll try with more volts when I get the new cooler

[gurusan]

thanks clemmaster. Much appreciated. Going to try now

[Boogerlad]

what is default vgddr?

[gurusan]

Thanks clem, I've just done a pencil vmem mod, bumped it up from 2.04v to 2.14v and so far am at 2400mhz (1200) stable

What are general "safe" voltage limits for gDDR3?

[Clemmaster]

I don't know for those, I've read up to 2.6v but it seems high to me so I may be wrong.

I'll check on Qimonda's datasheet

[gurusan]

I found the data sheet for these particular qimonda chips (HYB18H51232BF-10), but I don't really understand what I'm looking at :/
http://www.qimonda.com/download.jsp?...rev130_www.pdf

Perhaps someone else can take a look at that and let us know the max rated voltage?

[jason4207]

what is default vgddr?

It was 2.01v on my card.

Thanks clem, I've just done a pencil vmem mod, bumped it up from 2.04v to 2.14v and so far am at 2400mhz (1200) stable

What are general "safe" voltage limits for gDDR3?

I've read in another thread that 2.15v is safe for 24/7 operation, but don't quote me on that.

[Clemmaster]

2.5v max

http://www.qimonda.com/download.jsp?...rev100_www.pdf page 28.

[gurusan]

that still sounds high to me lol. I think I'll go 2.2v max and see how much I can squeeze out.

I would really like to hit 1250mhz as that will give a nice even 80gbps bandwidth

[jason4207]

I found the data sheet for these particular qimonda chips (HYB18H51232BF-10), but I don't really understand what I'm looking at :/
http://www.qimonda.com/download.jsp?...rev130_www.pdf

Perhaps someone else can take a look at that and let us know the max rated voltage?

It says absolute max is 2.5v, and recommended max is 2.1v.

Edit: too slow

[Miwo]

It says Absolute Max = 2.5v, Recommended Max = 2.1v
Considering stock is 2.0v, 10-15% is 2.2v-2.3v, which should probably be ok with active cooling over ramsinks I would imagine