Doing Vmod to my 7800GTX 256 tonight, wondering what Vgpu and Vmem everyone runs?

[Major]

Hey guys, I'm going to Vmod my 7800gtx 256 tonight and was wondering what everyone has been running on the Vgpu and Vmem??

What is the concensus on safe Volts ?

I really just want to bump both up a notch and leave it at that level. Not benching so I'm not goingt to try and squeze every last mhz out of them.

I'm goingt to be water cooling and in SLI, ram sinks and fan on cards.

From what I've read maybe 1.7vgpu and 2.5vmem ??

[Kasparz]

1.7Vgpu will be dangerous for 24/7 use.
Maybe 1.55-1.6V on water and 2.3Vdd for 24/7.
I use 1.5V biosmod and 2.24Vdd on my 7800gt with akasa cpu cooler 24/7@65C load.

[Vapor]

I used just a smidge under 1.7V (like 1.685V) for 24/7 on my core....never got above 50C, even at 650MHz. Memory I stopped gaining at around 2.6, so I dropped it to 2.55V for 24/7 and it was fine with RAMsinks and some good airflow. This was with an MCW-50, fwiw.

[Elfear]

ViperJohn recommends 1.66V max on the core for 24/7 usage (for watercooling). Not sure about the mem since I was using GTs which have Infineon chips.

[madgravity34]

For the gtx's VJ recommends 1.44 2d voltages which are 1.68 3d voltages and no more than 2.35v vdd.

[afireinside]

Not sure where he formulated 1.68v from but it seems like an ok max. I'd probably do 1.7. I have to max my GTs at 1.6 though because even with zalman coolers and a delta fan, they hit 70c loaded with single spaced SLI.

[Major]

Thanks for the input guys ;)

I think 1.65v and 2.3v sounds good

[madgravity34]

@AFI, the 1.68 is formulated because 1.44v in 2d is just around stock volts on the gtx's and at idle this is perfectly fine. Loading with 1.44 in 2d gives me 1.683d.

[eBoy0]

Isn't stock memory 2.2v? Pump it up... i learned the hard way, lethal = anything over 2.8, my card ran ar 3.06vddr for about 40 minutes.

[Major]

@AFI, the 1.68 is formulated because 1.44v in 2d is just around stock volts on the gtx's and at idle this is perfectly fine. Loading with 1.44 in 2d gives me 1.683d.

Well if VJ says to use 1.44v 2d and 1.68v 3d then I'll take his advice ;)

I just hope my hands are up to the Vmod soldiering task (I get the shakes) LOL

[Major]

Isn't stock memory 2.2v? Pump it up... i learned the hard way, lethal = anything over 2.8, my card ran ar 3.06vddr for about 40 minutes.

I've never gained much from the Vdd mods and running high Vmem. Like I said this is for a 24/7 rig and not for benching. So IMO 2.3-2.35 is comfortable for me. Reading posts it seems like atlot of folks were running 2.5v, but if VJ thinks thats too much for 24/7 then he's probably right

[kiwi]

I run like this:
24/7 water/good air: 1.55V, 2.3V

Benching
Water/cold air: 1.8V, 2.5V
DICE: 1.9V, 2.5V

Mem clock above 2.5V didn't increase.

[madgravity34]

Kiwi, was that score in your sig (3dmark05 one) done with dice on the card?

PS: Personally, I think that 1.68v is plenty for core voltage because with water those volts got me bench stable with no artifacts to the clocks in my sig. The memory was only at 1491 but it was running very tight timings.

[Major]

Thanks for the input :toast:

[Jort]

i used 1.78v and 2.75v on custom cold air SP92 heatsink + memsinks

only for benching :)

[Vapor]

You should gain A LOT on the VDDR mod....I went from 1500 stock voltage to over 1700 at 2.6 (on a modified BIOS with loose timings)....then flashed back to a tight timing one and got 1670 (vs. 1484 at stock). Definitely don't stop at 2.3V :)

[eBoy0]

Good luck major!!

[madgravity34]

One word on memory speeds, VJ informed me that the 256mb gtx's rarely will hit memory speeds like vapor's does. He told me that is why the gtx 512's are so hard to come by because only 10 - 15 percent of the cores off the wafers can handle memory clocks that high.

[s7e9h3n]

He told me that is why the gtx 512's are so hard to come by because only 10 - 15 percent of the cores off the wafers can handle memory clocks that high.
That and the fact that there's a shortage on GDDR3. Nvidia competes with both ATI and Microsoft for the allocation available.
BTW, I know of someone with a pair of 256GTX's (and I'm pretty sure VJ would know who I'm talking about) that have the capability to compete with some of the best 512GTX's around ;)

[eBoy0]

You should gain A LOT on the VDDR mod....I went from 1500 stock voltage to over 1700 at 2.6 (on a modified BIOS with loose timings)....then flashed back to a tight timing one and got 1670 (vs. 1484 at stock). Definitely don't stop at 2.3V :)

I hit 1690 with one of Dynasty's bios @ 2.8vddr

[Major]

Well I scraped doing the Vmod tonight, I killed one of my 7800 removing the POS Aritic Cooling Silencer5 :D

But I did get my MCW60 today and have ONE of them installed, so I'm back on water atleast.

[dogsx2]

Well I scraped doing the Vmod tonight, I killed one of my 7800 removing the POS Aritic Cooling Silencer5 :D

But I did get my MCW60 today and have ONE of them installed, so I'm back on water atleast.

Sorry I sold you the Koolance2.:(

[s7e9h3n]

Well I scraped doing the Vmod tonight, I killed one of my 7800 removing the POS Aritic Cooling Silencer5 :D

But I did get my MCW60 today and have ONE of them installed, so I'm back on water atleast.
YOu sure it's dead? How did it happen? Interested in getting rid of it? :p:

[Major]

YOu sure it's dead? How did it happen? Interested in getting rid of it? :p:

Yes it is very dead :(

I took off the AC5R3 on the first card without a hitch, took my time and cut all the Thermal tape and pads with a razor blade between the BGA and the HS. But on the second card, well I didn't take my time and ended up pulling OFF 2 of the BGA ram on the back side of the card.

Not a big deal, I've not killed anything in 3 or 4 months so I'm due ;)

Besides now I get to upgrade to 1900xtx or may even look at going ATI now ! LOL

[Major]

Sorry I sold you the Koolance2.:(


No I'm sorry I ever thought about using the AC5R3, what a total disapointed to begin with and now this ! lol

I'm glad I got the Exos2 back, I missed it really ;)

[n00b 0f l337]

going ATI now
Woot something good came of it. :)

[s7e9h3n]

Yes it is very dead :(

I took off the AC5R3 on the first card without a hitch, took my time and cut all the Thermal tape and pads with a razor blade between the BGA and the HS. But on the second card, well I didn't take my time and ended up pulling OFF 2 of the BGA ram on the back side of the card.

Not a big deal, I've not killed anything in 3 or 4 months so I'm due ;)

Besides now I get to upgrade to 1900xtx or may even look at going ATI now ! LOL
LOL...OK..I agree, it's dead :p: I wish I could destroy hW like that to justify spending even more money to upgrade :D If you can though, more power to ya :toast:

[Major]

Well I broke down and ordered a replacement 7800GTX from Newegg today. I know I know.... should have got something newer/better! lol

Anyway, I'll be back on track with my SLI setup and Vmods next week ;)

[Dynasty]

Well I broke down and ordered a replacement 7800GTX from Newegg today. I know I know.... should have got something newer/better! lol

Anyway, I'll be back on track with my SLI setup and Vmods next week ;)

Should of just waited for 7900gtx's out in march,
but hey I would of done the same also.
Hopefully, your new card does as good or better in clks. :)

[Major]

Should of just waited for 7900gtx's out in march,
but hey I would of done the same also.
Hopefully, your new card does as good or better in clks. :)

I'm sure I'll grab a set of 7900's too ;)

[VParis85]

Hey Major the soldering part is easy dont be afriad I had to resolder my gpu vmod several times i actually ripped of the one point where you solder to the chip and resoldered it back on a couple times to get it cleaned up a lil its pretty hard to break it unless you get alil crazy and start soldering thingd together that you shouldnt right now im running 1.65 vgpu and 2.3 vmem and am going to up it to 1.68 and 2.35 maybe 2.4. I am currently looking for a great bios and drivers to use if any one can help pls let me know!

[douirc]

Hey guys, I'm going to Vmod my 7800gtx 256

Major - you got a link to a good vmod guide? thinking about doing the same to my 7800gtx.

[Dynasty]

Major - you got a link to a good vmod guide? thinking about doing the same to my 7800gtx.

here:

http://www.malvescorner.net/7800.html

[douirc]

anything better? perhaps with pics of the final results?