The Simple & Concise 7900GT Voltmod Tutorial

[Crescent13]

wow, hard to believe someone with only 89 posts would be willing to do this for a forum that they hardly know. :thumbsup:


Sticky.

 

[Avalon]

Wow, fantastic guide!

STICKY!

 

[dman918]

3dmark05 (for me):
before: ~7800-7900 -> ~450/500
after: ~9900-10100 -> ~630/800 and ~650/850

Unfortunately, though the 650/850 works fine with no artifacting in 3dmark, there is a major lag within a couple of my games at those speeds. I can only get it without hiccups in BF2 and FEAR at ~630/800.

I do have a VF700 with memory heatspreaders on a 7900GT (non-CO).

 

[Live]

I'm I blind or does this guide just outline the 1.5 core voltage? I would like to start with the 1.4 and test for stability. Or do I just connect the the most right one in the picture and the most left one to get 1.4? http://fuzzybabybunny.smugmug.com/photos/65741906-O.jpg

 

[starwars7]

Originally posted by: ST

Originally posted by: aniruddha23
lil off direction but can someone give me before after 3DMark05 scores on the 7900GT after volt modding. anybody who has done this.

Stock (450/660) : 4695
OC (532/784 ): 5411
Volt Mod OC (685/885): 6559

So is the OC you're showing just using the Powerstrip program to OC your 7900?

What kind of increase are most people getting from OCing before they do the Volt Mod?

Thanks

 

[imported_ST]

Originally posted by: starwars7

Originally posted by: ST

Originally posted by: aniruddha23
lil off direction but can someone give me before after 3DMark05 scores on the 7900GT after volt modding. anybody who has done this.

Stock (450/660) : 4695
OC (532/784 ): 5411
Volt Mod OC (685/885): 6559

So is the OC you're showing just using the Powerstrip program to OC your 7900?

What kind of increase are most people getting from OCing before they do the Volt Mod?

Thanks

OC is standard non volt modded with Coolbits.
Volt Mod OC is done with ATI tool (just my preference)...

 

[starwars7]

Originally posted by: ST

Originally posted by: starwars7

Originally posted by: ST

Originally posted by: aniruddha23
lil off direction but can someone give me before after 3DMark05 scores on the 7900GT after volt modding. anybody who has done this.

Stock (450/660) : 4695
OC (532/784 ): 5411
Volt Mod OC (685/885): 6559

So is the OC you're showing just using the Powerstrip program to OC your 7900?

What kind of increase are most people getting from OCing before they do the Volt Mod?

Thanks

OC is standard non volt modded with Coolbits.
Volt Mod OC is done with ATI tool (just my preference)...

So the ATI tools are working on your 7900 GT without needing to physically mod your Card?


Also, as far as coolers, the NV Silencer 5 Rev. 3 does not explicitly have RAM sinks, but it does make contact with all the RAM, will that be enough?

Pic

 

[imported_ST]

Originally posted by: starwars7

Originally posted by: ST

Originally posted by: starwars7

Originally posted by: ST

Originally posted by: aniruddha23
lil off direction but can someone give me before after 3DMark05 scores on the 7900GT after volt modding. anybody who has done this.

Stock (450/660) : 4695
OC (532/784 ): 5411
Volt Mod OC (685/885): 6559

So is the OC you're showing just using the Powerstrip program to OC your 7900?

What kind of increase are most people getting from OCing before they do the Volt Mod?

Thanks

OC is standard non volt modded with Coolbits.
Volt Mod OC is done with ATI tool (just my preference)...

So the ATI tools are working on your 7900 GT without needing to physically mod your Card?

no...volt mod is still needed. volt mod only changes the voltage regulation to the cpu, it does not automaticallly change the clock. you need a tool like ati tools or powerstrip in order to change the clocks higher afterwards.

 

[dman918]

I'm using coolbits right now, but I used rivatuner to get the high OC. I am only using coolbits because it seems I have those difficulties at higher OCs anyway, so coolbits serves my purpose. Maybe I will experiment with clocks more this weekend...

 

[dman918]

Originally posted by: ST

Originally posted by: aniruddha23
lil off direction but can someone give me before after 3DMark05 scores on the 7900GT after volt modding. anybody who has done this.

Can't help you with 3DMark05 scores, but here's some before and after 3DMArk06 scores:


Stock (450/660) : 4695
OC (532/784 ): 5411
Volt Mod OC (685/885): 6559

Wow, I thought my 3dmark06 score was less than 5000 with the OC. I need to run it again and see.

 

[the Chase]

Sweet guide. The photos are awesome- very clear and easy to follow.

 

[Kaido]

fuzzy, you did an excellent job on this, I can't believe I didn't see this before! This really clears things up. Thank you!

 

[nib95]

Awesome thread, so very clear and easy to use.
It's a shame the people of Xtreme Systems forums are not quite so helpful nor kind as to do such a guide.

 

[Sunrise089]

Can someone explain the relative importance of ramsinks and aftermarket cooling? Should the stock cooler not be used on an OC'd card at all? The nvSilencer card seems to contact the RAM directly, so how would you add the ransinks? If you use the nvSilencer, do you just not add the RAM sinks, or what? And if you use the VF700 from Zalman (it costs more, so I'd rather not), does it automatically cool the memory if you're using RAM sinks? More than anything else, I'm not sure how you could even add RAM sinks and not have active cooling on them if you followed the directions to add an aftermarked cooler first. Finally, is there anywhere you need to add RAM sinks on the back of the card? I'm not sure how you would add cooling there.

 

[TheRyuu]

Originally posted by: Sunrise089
Can someone explain the relative importance of ramsinks and aftermarket cooling? Should the stock cooler not be used on an OC'd card at all? The nvSilencer card seems to contact the RAM directly, so how would you add the ransinks? If you use the nvSilencer, do you just not add the RAM sinks, or what? And if you use the VF700 from Zalman (it costs more, so I'd rather not), does it automatically cool the memory if you're using RAM sinks? More than anything else, I'm not sure how you could even add RAM sinks and not have active cooling on them if you followed the directions to add an aftermarked cooler first. Finally, is there anywhere you need to add RAM sinks on the back of the card? I'm not sure how you would add cooling there.

Now, I want you to take a loot at the card. No really I'm serious. Take the card out of the case and put it on the desk and LOOK at it. You see that little Box thing? Thats the HS. Now look at a picture of a 7900GTX HS. See the difference?

You are going to attempt to OC to near 7900GTX speeds with that little, dinky, crappy HS? Plus the RAM isn't even cooled. If you do the RAM voltmod then you screwed cause the ram doesn't throttle. It'll just burn up and die.

The next question I have to ask is WHY NOT. The NV Silencer Rev. 3 is like 20 bucks. Thats pretty cheap and it cools the card well (also does the ram too). Your going to be pushing GTX level volts into the card. As well as additional volts for the ram. Which will produce more heat.

Now I'm not saying that the stock cooler couldn't handel the increaed voltage and temperature load. I'm just saying doing take the risk when a GOOD third party HS is 20 bucks.

 

[Sunrise089]

Originally posted by: wizboy11

Now, I want you to take a loot at the card. No really I'm serious. Take the card out of the case and put it on the desk and LOOK at it. You see that little Box thing? Thats the HS. Now look at a picture of a 7900GTX HS. See the difference?

You are going to attempt to OC to near 7900GTX speeds with that little, dinky, crappy HS? Plus the RAM isn't even cooled. If you do the RAM voltmod then you screwed cause the ram doesn't throttle. It'll just burn up and die.

The next question I have to ask is WHY NOT. The NV Silencer Rev. 3 is like 20 bucks. Thats pretty cheap and it cools the card well (also does the ram too). Your going to be pushing GTX level volts into the card. As well as additional volts for the ram. Which will produce more heat.

Now I'm not saying that the stock cooler couldn't handel the increaed voltage and temperature load. I'm just saying doing take the risk when a GOOD third party HS is 20 bucks.

Wizboy: Thank you for the response, and for taking my post very out-of-context. If you re-read it carefully, you will see that nowhere did I say I actually planned on doing the mod on stock cooling, or I thought about running "near 7900GTX speeds" on the stock HSF. In fact, I asked about any overclocking at all with the stock HSF. What I am looking for here is some sort of cut-off point. Clearly the stock cooler is OK for stock speeds. It probably isn't for volt-mod speeds, but there are plenty of speeds in between. I was just wondering if an nvSilencer is needed for any OC at all or only for a fairly agressive one. I still will buy the silencer in either case, I just wanted a feel for how close these cards were running to their max speeds from the factory.

My second question adressed the RAM sinks. Once again, I'm not proposing not using them, I'm commenting on the fact the OP makes two seperate reccomendations - 1) Use aftermarked cooling. 2) Use active cooling on the RAM sinks. I'm wondering why they aren't lumped together, since as far as I know the Zalman cooler is placed where active cooling is automatic, and the Silencer doesnt allow for RAM sinks at all, since it directly contacts the RAM.

I'm not sure on this last point however, so I asked. To make myself perfectly clear - if you are using an aftermarket cooler, which cooler (if any) would take the place of RAM sinks, and which cooler (if any) would not count as the active RAM sink cooling recomended.

 

[CP5670]

This is a little off topic, but has anyone here done the voltmod for the 7900 GTX? It's not quite as simple as this one, but I'm wondering if it's still possible to get some nice gains on that with just the standard cooler (which seems to be overkill for the stock speeds/voltages).

 

[TheRyuu]

Originally posted by: Sunrise089

Originally posted by: wizboy11

Now, I want you to take a loot at the card. No really I'm serious. Take the card out of the case and put it on the desk and LOOK at it. You see that little Box thing? Thats the HS. Now look at a picture of a 7900GTX HS. See the difference?

You are going to attempt to OC to near 7900GTX speeds with that little, dinky, crappy HS? Plus the RAM isn't even cooled. If you do the RAM voltmod then you screwed cause the ram doesn't throttle. It'll just burn up and die.

The next question I have to ask is WHY NOT. The NV Silencer Rev. 3 is like 20 bucks. Thats pretty cheap and it cools the card well (also does the ram too). Your going to be pushing GTX level volts into the card. As well as additional volts for the ram. Which will produce more heat.

Now I'm not saying that the stock cooler couldn't handel the increaed voltage and temperature load. I'm just saying doing take the risk when a GOOD third party HS is 20 bucks.

Wizboy: Thank you for the response, and for taking my post very out-of-context. If you re-read it carefully, you will see that nowhere did I say I actually planned on doing the mod on stock cooling, or I thought about running "near 7900GTX speeds" on the stock HSF. In fact, I asked about any overclocking at all with the stock HSF. What I am looking for here is some sort of cut-off point. Clearly the stock cooler is OK for stock speeds. It probably isn't for volt-mod speeds, but there are plenty of speeds in between. I was just wondering if an nvSilencer is needed for any OC at all or only for a fairly agressive one. I still will buy the silencer in either case, I just wanted a feel for how close these cards were running to their max speeds from the factory.

My second question adressed the RAM sinks. Once again, I'm not proposing not using them, I'm commenting on the fact the OP makes two seperate reccomendations - 1) Use aftermarked cooling. 2) Use active cooling on the RAM sinks. I'm wondering why they aren't lumped together, since as far as I know the Zalman cooler is placed where active cooling is automatic, and the Silencer doesnt allow for RAM sinks at all, since it directly contacts the RAM.

I'm not sure on this last point however, so I asked. To make myself perfectly clear - if you are using an aftermarket cooler, which cooler (if any) would take the place of RAM sinks, and which cooler (if any) would not count as the active RAM sink cooling recomended.

Uh, sorry?

Alright, the stock cooler is ok for any overclocking. As far as a 7900GT can go on stock volts, the stock cooler is fine. You can even do the vgpu mod on the stock cooler, although your temps would be rather high.

For the RAM sinks, for any aftermarket cooler that doesn't cool the RAM directly (like the NV Silencer), me personally would get the OCZ Copper ones. I'd even spread out the fins on them a little like the Zalman ones. And then yes, pretty much the fan on the aftermarket cooler would take care of the "active part" of the cooling. Since I have watercooling I decided to place a fan by the video cards too since there's little airflow down there.

Did I get it right this time?

 

[Sunrise089]

Originally posted by: wizboy11

Did I get it right this time?

You did just fine.

Follow up: If I want aftermarket cooling I seem to have 2 options:

NV Silencer and Copper RAM sinks (combined $39 shipped)
or
ZALMAN VF700 ($36 shipped) and my free Aluminum RAM sinks that were included with my motherboard.

Which option would be better in terms of performance/safety? Cheapest of all would be my aluminum RAM sinks with the NV Silencer, but not sure if that's enough RAM cooling.

 

[Kaido]

Originally posted by: Sunrise089

Originally posted by: wizboy11

Did I get it right this time?

You did just fine.

Follow up: If I want aftermarket cooling I seem to have 2 options:

NV Silencer and Copper RAM sinks (combined $39 shipped)
or
ZALMAN VF700 ($36 shipped) and my free Aluminum RAM sinks that were included with my motherboard.

Which option would be better in terms of performance/safety? Cheapest of all would be my aluminum RAM sinks with the NV Silencer, but not sure if that's enough RAM cooling.

Personally, I'm going to go a bit crazy on my 7900gt when I order it next month:

-eVGA 7900gt 500/1500mhz
-vmod/mem mod with conductive pen/pencil
-Zalman vf900 aftermarket cooler
-Arctic Silver 5 for the Zalman
-OCZ copper ramsinks
-Arctic Silver thermal adhesive for the ramsinks

This should provide both quieter operation and cooler performance. Or it may just be a waste of $40. At least my card will look cool

 

[fuzzybabybunny]

Originally posted by: Sunrise089
My second question adressed the RAM sinks. Once again, I'm not proposing not using them, I'm commenting on the fact the OP makes two seperate reccomendations - 1) Use aftermarked cooling. 2) Use active cooling on the RAM sinks. I'm wondering why they aren't lumped together, since as far as I know the Zalman cooler is placed where active cooling is automatic, and the Silencer doesnt allow for RAM sinks at all, since it directly contacts the RAM.

The reason why active cooling and RAMsinks aren't lumped together is because some people, such as myself, watercool their video cards. What usually happens with aircooling is that the main fan over the video card core also blows a bit of air onto the RAMsinks. With watercooling, since there is no fan, there is no residual air that's being blown on the RAMsinks, hence the need for a fan and to remind the watercoolers out there that they still need airflow for the RAM.

As for the Silencer and RAMsinks, I don't think you'll need to even get RAMsinks if you get the Silencer? Looking at its picture, shouldn't the RAM heat just travel up to the main heatsink through the copper that contacts the RAM? The copper contacts do look mighty thin though, so I guess RAMsinks are still needed.

 

[Live]

Nobody can answer my question above?

 

[crazylegs]

here you go Live a little link showing 1.4V connection:

http://www.xtremesystems.org/forums/showpost.php?p=1355686&postcount=162

GL

Thats what i'm going to go for... first of all anyway
- if my 7900GT EVER arrives!

 

[Live]

Thank you very much crazylegs!

 

[crazylegs]

Heres another showing various options...

http://img.photobucket.com/albums/v312/spazmaster666/7900vmoddiag6qw.jpg

EDIT-

there is also a picture somewhere that shows how to get 1.55V (not necessary though!)

to do this another line is drawn from the same point of origin in a line straight down and then right in a right-angle.

this further line adds another cumulative 0.5v and infact any combination is achievable from 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55

i'm going to go for 1.4 then see what OC and TEMPS are like with my vf900 (but not great case airflow)

enjoy!