*Official* GTX 275 Thread

[Open1Your1Eyes0]

If anyone is interested in trading their GTX275 for a 9800GX2 please PM me or visit my sale thread in my signature.

PS: Great job on the thread Lyric!

[Zenki]

Your going to not want to exceed 90C when under load for a long period of time. So long as you dont go and jack up the values without slow testing you will quickly see the limits. If you see yourself getting close to where many are topping out then take extra care to test. I suppose as with all overclocking you run some risk of causing damage if you were to run a card at dangerous values.

[Sabis]

Well, so far the highest temps I've seen have been 65. I keep the fan settings fairly high, keep my apartment fairly cold, and keep my comp somewhere it can breathe. And yeah, I've noticed it wants to simply crash out when i go over certain values. Am hoping a slow bump past them will get me where I want. Just really hope it's not a limit of power form the PSU that would annoy me

[Zenki]

Well decided tonight to attempt a small increase more in the OC as my fan speed is staying pretty low still and temps are not getting me worried.

So far tonight we are up to 701/1577/2442, only touching 58% fan duty and running stable through ATI Tool and FurMark, will see how things go through 3D Mark and some games before I set this to default but would seem this card is happy to keep going. Also been thrilled that this card has nearly zero whine under load which always ticks me off when I hear it.

[Zenki]

After tweaking have came up with a nice stable overclock for the card, with all benchmarks and tests running without issue. My goal was to take the clock up to at least the specs of the eVGA GTX 275 FTW edition and was able to do so with the core clock and memory, found more headroom in the shader clock so kept going untill 3DMark 06 began to have a driver related issue (perhaps based on having to use Nvidia beta drivers for this card.

Stock Values: 633/1404/2268(1134)
OC Values: 713/1584/2520(1260)

So a 12.6% increase on the core, 12.8% shaders and 11.1% for the memory. While I do not have one to compare against I would have to assume at these numbers I am at least matching the performance of a GTX 285 at stock clocks. Will be posting up pics and a summary of my system overclock that I have done over the period of this week.

[DannyM]

I have a BFG GTX 275 OC. Great upgrade from my BFG 8800GTX OC.
Here are my overclock settings: http://www.techpowerup.com/gpuz/w3q5y/

I'm thinking about getting another one and running SLI after I finish my i7 build.

[Zenki]

Originally Posted by DannyM

I have a BFG GTX 275 OC. Great upgrade from my BFG 8800GTX OC.
Here are my overclock settings: http://www.techpowerup.com/gpuz/w3q5y/

I'm thinking about getting another one and running SLI after I finish my i7 build.

Hey just to let you know that values that you have OC'd to are not exactly what is shown by GPU-Z. For instance your shaders are shown as 1605MHz but will in fact be running at 1620MHz. As well your memory is set to run at 1282MHz but it will in fact be running at 1269MHz.

This is all due with the fact that Nvidia cards work in a series of "steps" with their true clock speeds. There is a great write up done by Mikecdm http://www.overclock.net/nvidia/4976...er-straps.html. He explains how these steps work and that when you are overclocking you are in fact just switching between these steps with your values entered in.

I found with my GTX 275 SC that having the shaders at 1620 began to cause DX9 stability issues so I backed them off to the next level down of 1584MHz. Would be interested to hear your temps and how you tested that core clock of 743MHz as that is very quick for these cards.

[Lyric]

Originally Posted by Zenki

I found with my GTX 275 SC that having the shaders at 1620 began to cause DX9 stability issues so I backed them off to the next level down of 1584MHz. Would be interested to hear your temps and how you tested that core clock of 743MHz as that is very quick for these cards.

I had that same issue as well! 3DMark06 would crash, but 3DMark Vantage would run through no matter, no problem. I guess its because 3DMark06=DX9? and 3DMark Vantage = DX10?

It would run at 1620 through vantage, but not 3dmark06.
It runs at 1584 though through 3DMark06 and Vantage stable @ 720/1584/1215, and it will fold just fine at 1620 as well. (haven't tried to oc the memory much as it isn't really worth it, i just bumped it up one notch for kicks cause I didn't like the number 1181, lol.

[Zenki]

Originally Posted by Lyric

I had that same issue as well! 3DMark06 would crash, but 3DMark Vantage would run through no matter, no problem. I guess its because 3DMark06=DX9? and 3DMark Vantage = DX10?

It would run at 1620 through vantage, but not 3dmark06.
It runs at 1584 though through 3DMark06 and Vantage stable @ 720/1584/1215, and it will fold just fine at 1620 as well. (haven't tried to oc the memory much as it isn't really worth it, i just bumped it up one notch for kicks cause I didn't like the number 1181, lol.

I am having to think it is driver related because the temps for the card do not get above 88C even in FurMark when I am at 1620 on the shaders. I was playing some Portal before and did notice some issues at 1620 in there as well. For now I have set them back to 1584 as its only a tiny difference in games.

[DannyM]

Originally Posted by Zenki

Hey just to let you know that values that you have OC'd to are not exactly what is shown by GPU-Z. For instance your shaders are shown as 1605MHz but will in fact be running at 1620MHz. As well your memory is set to run at 1282MHz but it will in fact be running at 1269MHz.

This is all due with the fact that Nvidia cards work in a series of "steps" with their true clock speeds. There is a great write up done by Mikecdm http://www.overclock.net/nvidia/4976...er-straps.html. He explains how these steps work and that when you are overclocking you are in fact just switching between these steps with your values entered in.

I found with my GTX 275 SC that having the shaders at 1620 began to cause DX9 stability issues so I backed them off to the next level down of 1584MHz. Would be interested to hear your temps and how you tested that core clock of 743MHz as that is very quick for these cards.

I am not sure what strap its on. Here is what the NVidia Control Panel - Performance - Tech Support Log File Says:

Current Time = Mon May 04 15:57:57 2009 Central Daylight Time

========== Driver Version Information ==========

Graphics Driver		182.50 (7.15.11.8250)

========== GeForce Information ==========

GPU 1: GeForce GTX 275

========== GPU's Core and Memory Speed Information ==========


GPU Core Speed = 743
GPU Memory Speed = 1282

GPU Shader Clock Speed = 1605

To test stability and temps I ran FurMark. It didnt crash or anything and it raises my temps to about 75 to 80c with fan at 80%.