Originally posted by boredgunner

[http://www.evga.com/forumsarchive/tm.asp?m=100598109]

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Some people are unsure on how to overclock the GPU.  Quite frankly, the GPU is the easiest thing to overclock in a system.  Lets start from the beginning.  

The first thing I recommend is to grab some useful programs and the latest NVIDIA WHQL drivers.  The programs I recommend are EVGA Precision 1.7.1 (for the overclocking/monitoring), GPU-Z 0.3.4 (monitoring/GPU info), and a stress testing program for artifact testing.  OCCT has two tests - one for VRAM as well.  For this guide I'll be using ATItool 0.26.

ForceWare 190.62 WHQL Driver

• WinXP 32 bit
• WinXP 64 bit
• WinVista 32 bit
• WinVista 64 bit

Proper uninstallation/installation of video drivers (Vista, in XP it should be somewhat similar):

• Download and install Driver Sweeper or something similar.
• Download desired driver.
• Right click on computer, properties, click Device Manager (on left)
• Select your display device (video card), uninstall video device software.
• Delete driver folder (located in C:\NVIDIA)
• Reboot in safe mode (repeatedly hit F8 during boot sequence).
• Run Driver Sweeper or your equivalent.  Only clean Display and PhysX driver.
• Reboot.
• Install your desired driver.
• Reboot.

When installing new drivers, make sure all anti-virus software is disabled.

EVGA Precision 1.8.0 Download

GPU-Z 0.3.4 Download

ATItool 0.26 Download

OCCT Download

Furmark 1.6.5 Download

Driver Sweeper 2.0.5 Download

For those of you who don't know, artifacts occur when your GPU is overclocked too high and/or your temperatures are too high (but not high enough for a shut down).  If you get artifacting right out of the box with good temperatures and you did the proper method of installing new (and different) NVIDIA WHQL drivers, I suggest you RMA your GPU.  Make sure your temperatures stay below 105 degrees Celsius, that is the max most cards can handle.  It is best to stay below 90 degrees Celsius, artifacts can occur before 105.  

For this guide I'll be using my primary video card for example, an EVGA GTX 260 CORE 216 (55nm).  This is the vanilla (default) version which came at the factory clocks.

Factory Settings:

• Core Clock: 576 mhz
• Shader Clock:1242 mhz
• Memory Clock: 999 mhz (1998 mhz effective data rate)
• Fan Speed: Auto (40%)

Uh oh, we ran into another confusing term here.  

Effective data rate?  What does that mean?  My card was supposed to come with 1998 mhz memory but it is shown as 999 mhz!

High end video cards use double data rate memory, usually GDDR3 or on several ATI cards they use GDDR5 as well.  Multiply the memory clock EVGA Precision/GPU-Z shows to get the effective data rate, which is usually what is advertised.  

999 mhz x 2 = 1998 mhz

GDDR5 memory on the other hand is really QDR or Quad Data Rate.  Rather than multiplying by 2 you multiply by 4.


Now onto the overclocking.  I open up EVGA Precision 1.6.1 (1.7.1 was not released when I made this guide), GPU-Z 0.3.3 (0.3.4 was not out yet), and ATItool 0.26.  My core clock is 576 mhz, shader clock is 1242 mhz, memory clock is 999 mhz just as it should be.  Core/shaders are linked and fan speed is auto, or 40%.  Notice with EVGA Precision 1.6.1 you can select other video cards to overclock separately.  The monitoring graph can be removed from the box and expanded to show additional information.  Very useful.  Do not enable Apply at startup until you've ensured stability!

By boredgunner at 2009-04-13

Lets get started.  Unlink the core/shaders, and set fan speed to manual and raise it a little.  You can push the sliders up, or enter a number and it will give you your desired clock speeds.  Overclock in small increments, no more than 27 mhz at a time for the shader clock.  The core clock should run at a maximum of 1/2 the shader clock.  Memory clock should be raised in small increments too, no more than 25 mhz.  After the first small overclock, select the scan for artifacts feature on ATItool.  So first I unlinked core/shaders and set fan speed to 60% (it went to 61% on it's own).  

I increased the core clock speed from 576 mhz to 600 mhz, shaders from 1242 mhz to 1280 mhz, and memory clock from 999 mhz to 1025 mhz.  Yeah a little more than 25 mhz increments but I've overclocked this card before, I know what it is capable of.

By boredgunner at 2009-04-13
Run ATItool for a little while (several minutes) and see if you run into any artifacts.  I didn't, so lets move on.

Lets bump it up to GTX 260 SC speeds, 626/1350/1053 (core/shaders/memory).  I'm making pretty large heaps because I've overclocked this card before.

By boredgunner at 2009-04-13
Run ATItool.  Still success, lets move on.

Bumped up to FTW speeds.  No errors yet.

By boredgunner at 2009-04-13
Run ATItool.  I ramped the fan speed up to 80% to keep the temperatures down.  It got quite noisy, but I don't really care.  Still success, lets move on.

Lets push a little bit further, 684/1476/1190.

By boredgunner at 2009-04-13

Does overclocking void my warranty?
Not if you have an EVGA card.  I can't speak for anyone else, sorry.

I ran into an error.  What do I do?  
Lower the speeds a little bit.  If you get the nvlddmkm stopped responding and has recovered error, try lowering the memory clock first.  If it still persists, lower the core.  If it still persists, lower the shader clock too.  Lower them to the last successful clock you had them at, and move forward again a little bit more.  Sometimes you can get a BSOD from the same error.  These blue screens are pretty detailed and usually say nvlddmkm stopped responding and has failed to recover or something along the lines of that.  Follow the same procedure.  

I can't overclock as high as others who have the same card.  Why is this? 
Not all cards are the same, some overclock further than others.  Water cooling your GPU can help you reach higher speeds.

How much does GPU overclocking affect performance?  
In games, the difference isn't that noticeable unless you reach a very high overclock.  In GPU heavy benchmarks such as 3DMark Vantage you'll get a nice increase in your GPU score and even your overall score if you've achieved a decent overclock.

EVGA offers SC, SSC, and FTW models.  What is the difference?
These are factory overclocked, guaranteed to work above the default speeds.  In my opinion the SC/SSC models aren't worth it when there is a FTW model for that card, from what I've read these are the parts that fail to reach the FTW spec but I'm not too sure on this.  The FTW cards are priced very high but they also have very nice overclocks on them.  Same goes for the SSC on cards that have no FTW model.  I passed the FTW speed on my GTX 260, but failed to reach the EVGA SSC speed on my PNY 9600GT (9600GT SSC comes at 740/1836/975).

I've ran into my max overclock.  When you do, you can upload a validation file on GPU-Z for bragging rights

Here is the validation for my GTX 260.  19% increase across the board.  Not bad.

http://www.techpowerup.com/gpuz/cun93/

One for my PhysX Processing Unit too, 9600GT.  11% increase on the core/shaders, 6% on the memory.  Disappointed, but oh well.

http://www.techpowerup.com/gpuz/2qfha/

My new PhysX processing unit remains at stock speeds, since I can't exactly stress test it unless I make it my primary card.

http://www.techpowerup.com/gpuz/8mun3/

Final Settings:

• Core Clock: 684 mhz
• Shader Clock: 1476 mhz
• Memory Clock: 1188 mhz (2376 mhz effective data rate)
• Fan Speed: 80%

☢

i'm having a problem when running atitool version 0.26..

when i run any of the utilities it gives this error:

"the video card you selected for overclocking in atitool does not seem to be used by windows
visual test has been disabled
to fix this go to display properties, settings and enable the monitor output of the card."

i'm not sure what its asking me to do as i only have one monitor connected and i'm getting a display, maybe i'm just not understanding what its telling me, can you help me please?

my pc specs are:

Windows Vista Ultimate 32-bit SP1
Intel Celeron D @3.33Ghz
Nvidia GeForce 9400 GT @1GB vram
evga precision reports:
core clock @ 550
shader @1375
memory clock @ 400
my mother board:
Gigabyte Tech. 945GCMX-S2

This guide is exactly what I was looking for.  THANK YOU!

Is there a version of ATiTools that works with Win 7? I'm getting an unsigned driver error and it won't run test properly on my system.

Try OCCT or Furmark instead of ATItool.

I have an 8800gts 640MB this guide is pretty good but a very imporant aspect you are missing is that the shader and core clocks are linked.  I wish i had the link to the site I find the information on, but i don't.   basically the core clock cannot be increased in single digit increments.  Even if you disable the link between the shader and core clock they are not completely independent.  the formula to figure out speeds is the following:
 
OC shader clock = Default shader clock / Default core clock * OC core clock.
 
The problem with using icrements of say 5 MHz at a time to determine highest core OC, is that afeter you determine your shader OC in the same fashion the core clock may be runniong at say 650 MHz but is really only function at 640 MHz (i'm just making up numbers) because the shader clock has an OC setting which is incompatible with the core oc.  the problem you have is heat. you could slow dow the core and get the same benchmark scores with less stress on your card.  hopefully someone can make heads or tails of my terrible attempt at explaining something i know little to nothing about.  Hope this helps someone out there. 
 
I hadn't thought twice about my OC i've been running for a couple years until i ran into some randome site looking for something tottally different.  I think the problem with most of the "OC guidss" people post regarding video cards is that they aren't meant as guides in the first place, but simply a websites comparison of how different cards oc compared to each other.  This guide thread is the second best thread I found, the first being the one which i can no longer find a liink to.  The relationship between these two clocks is also why some programs read different speeds than others if the clocks are not synced.  One might be reading the 650 you think your card is running at while another is reading the 640 which is the actually speed the card is utulizing. If someone can make retype my post so that people can understand my random bantering then please delete this scrambled jargon of a reply i wrote. 

I would just link those too. IMO its not worth change it.

Your shader clock maybe off because it runs on shader straps. So for an example if you overclock your shader to 1337 and its in the straps 1300 - 1340 it may just only display it ask 1337, even if your clock is at 1300 all the way to 1340. 

I don't have a list for you card. So i can't help you there. 

I put a reply for originally because I found it interesting and it really surprised me that out of all the overclocking guides information and software this small but vital piece of information is missing.  I was mostly joking about rewriting it also, I was in a rush but wanted to make sure i was underrstood.  Actually I did manage to Jack my settings up, it was a mouse click error.  I had two program's attempting to change the clocks (rivatuner was one, and I'm sure where the problem lies).  I thought i had closed gputool, i was running the find max feature. Was a bit ironic.

How do you get it back to default settings? My core clock was at 301 and i cant move the bar down to 301. When not useing OC tool my default settings are core clock 301 and when i start up the OC precision tool with out applying anything it jumps up to 576 core clock. Dont like my computer to run like this all day with out even applying any OC to it.

1in1class


How do you get it back to default settings? My core clock was at 301 and i cant move the bar down to 301. When not useing OC tool my default settings are core clock 301 and when i start up the OC precision tool with out applying anything it jumps up to 576 core clock. Dont like my computer to run like this all day with out even applying any OC to it.

It is downclocking to save power and run cooler.

No it went up. When i start my computer up i click on precision tool and my settings are at default, core clock at 301 shader clock at 602 and memory clock at 100. This is at default befor applying anything. Then it just jump up to core clock 576 shader clock 1242 and memory clock 999 and i did not apply anything. How do i get it back to default settings?

Sorry default for precision tool is at core clock 576 shader clock 1242 and memory clock 999. When i start precision tool with out applying anything it says core clock at 301 shader clock at 602 memory clock at 100. Then it just jump up to 576/1242/999, and i did nothing. My tep goes from 46c to 56c. Im asking how to get it back down to 301/602/100 as it was when i start my computer up at factory settings.

576/1242/999 are the default clocks for your card.

It downclocks to 301/602/100 when it is not in use. This is to save power and lower the heat. 

It jumps to default clocks when you have a 3d app running. With precision(1.9.4) you can check which program is causing it to go into 3d mode. Just open up precision and click the I to the left of the program(below the graphs)

Yha it downclocks to 301/602/100 when i first start it up, then it just jump to 576/1242/999 with out me doing anything when its not in use. How do i get it back to downclock as if i was not useing it? 3d it says nothing about 3d?

If i OC, how would i get the settings back to 301/602/100 when im done OC? Thank you for helping me with this, just trying to get it to where it goes back to the way befor i OC.

You can set 3D and 2D profiles in later versions of EVGA Precision (use 1.9.4) and MSI Afterburner 1.6.0.

? i click on the I and it says nothing about 3d or 2d in it. I only got 1.9.4 i dont know what MSI Afterburner 1.6.0 is?

GPU1
Display device: Geforce GTX 260
Display driver: 8.17.12.5721, Forceware 257.21
On-board memory: 896MB
Bios: 62.00.50.00.50

thats all it says in the I.

Look in the options tab, I believe the icon is like a wrench or something.  The I stands for information.

Ok i look in the precision properties. What am i looking for there is nothing there that says 2d or 3d.

Look in the "Profiles" tab.

K got it, it says 2d not assigned and 3d not assigned.

If i am OC and im done OC how would i get it back to normal settings? Like 301/602/100 as if i was befor i OC.

Its not jumping to 576/1242/999 now. Dont know why it did that, but i restart the computer and its at normal 301/602/100 now. But if i OC and then get done with the OC how do i get it back to 301/602/100 like it was befor i OC?

Set 2D to 301/602/100 if you can, if not then set them as low as you can.  Auto fan is fine.  Set 3D to the standard 576/1242/999 or any stable overclock that you got, with a fan speed of whatever keeps your temps low enough without being too loud for you.  I used a 70% fan on my GTX 260s.

K ill try that out, but if i cant get it to 301/602/100 then there is realy no way of getting it back to that once you OC it right? Is there an reason why it jumps like that? Even when im not OC? You have been an realy big help thank you.

i've got a GTX 470 SC, and i took it to 750/1440/(stock)1701 @ 80%.  how much higher can i go on room air?  my scores jumped up significantly from stock clock (625/1250/1701) in 3dmarkVantage, from 17200 somethin to 20088 now.  i kinda wanna get a bit higher, but a)dunno if my psu'll handle it and b) as it stands im cappin at 78-79C maxload, idleing at 50-51C.  any info'll be appreciated.

How far you can go on air depends on the case/airflow setup and ambient temps can play a part in it.  Which PSU do you have?  

just out of interest, I have overclocked my GTX460m by 119mhz on the core, shaders and memory. GPU-Z and precision are telling me that after around 3-4 hours of solid gaming on black ops that my GPU temp is 69 degrees ( this is a laptop and i know it is risky but im doing it anyway) I presume my core temp is ok, but is there a utility that allows you to view the RAM  temp? as im worried that this may be too hot. I have ran ATI tools and getting no artifacts on test. The only thing that worres me is that if i overclock by 5mhz more, thermal throttling cuts in and lowers the speeds to 405, 405 and 805 mhz. It stays this way until reboot which i have read is normal. For now i have left the speeds at standard. Are there any signs that GPU ram is too hot?

I'm running my 450 @ 925/1850/2000    Stock numbers are 822/1645/1804
Everythings running great, no issues. 

EVGA GeForce 9500GT ddr2 512mb.
Default:
~550mhz Core
~500mhz Memory
~1375 Shader
 
 
First Error during a "Find Max Setting" for Memory mhz
~600mhz Core
~560 mhz Memory(It triggered a stop but OC didn't pick up anything)
~1500mhz Shader