260M overclocking (M15x)

[Mr Pras]

I just wrote this in a long thread so thought it might be useful if I post it here.

I was just telling a bit about my experience overclocking the 260M by upping the voltage, what the benefit might be and how to do it..

This is an example where I've pushed the voltage up (you only have one option to up it to) from the standard clocks of 550/950/1350 to 700/1100/1750 (27%/16%/30% overclock)

700/1100/1750 runs without glitches on 1.03V but on 1V it produces some artifacts. I couldn't push it much further with the higher voltage (720/1100/1800) would be the absolute limit.

But without the higher voltage it would totally bug out at that frequency, and I'd have to reset or drop in and out of standby to fix it.

It allowed me to run at a slightly higher clock (before the voltage I used to run safely at 640/1000/1600) so with the extra performance, the games are improved slightly for sure.

When running furmark with the higher clock I did experience throttling (5 seconds every 30 seconds roughly) and when I put the screen brightness to full it was more 15 seconds and 15 seconds.

Other than that, all the games I played ran fine except GTA IV which throttled for 5 seconds every 30 (roughly).

So yeah, upping the voltage allowed for a higher overclock but it involves a lot of risk! You have to pull your bios off the video card, mod it and flash it back and there is no fallback on these machines (As far as I know) if it goes wrong.

If you are willing to take the risk, you should use NVFLASH to download the video rom and mod it with NiBiTor. My modded bios contains only 2 changes to the performance 3D mode - Stock clocks are 640/1000/1600 and voltage is 1.03V.

One strange issue, I had to change to subsystem ID to flash it back. When I downloaded the rom from the video bios the subsystem was 02A1 but when I tried to flash it back it said that it was mismatched because the board had a subsystem of 02A2. Bizarre, but anyway - changing the id to 02A2 fixed that.

So now I have a very stable overclock as standard and push it to 700/1100/1750 when I want the performance and the game doesn't throttle.

I tried some other changes but only had problems.. Tried changing the other clocks to make them a little slower. This should have made the computer quieter in all modes except performance 3D (which is the only one where you really need a lot of power). The other modes can be quite slow since you usually don't use much of the GPU or you want the full power. (The video decoder is the same speed whatever your clocks are).

I had a lot of complications when trying to start up with that and had to try several liveCDs to get to the NVflash app to work (because it needed some specific service). Basically, if you mod it only touch the performance 3d clocks and voltage and if you found this post too technical - DON'T BOTHER, YOU MIGHT BRICK YOUR MACHINE - and dell will tell you that it's your fault so no warranty!!

[dttran83]

Can your overclocked run ATI Tool scan for atleast two hours stable? I don't think using game to test it is good enough. I think alot of people do that, they use crysis and play for 20 minute and if it doesn't crash then they consider it a stable clock.

[Villosa]

Actually, using a synthetic test to test for stability is less accurate than using a game/s. ATITool will be stable for me for a long period of time but running 25 cycles on Crysis will cause it to crash out. That is not considered stable.

Running benchmarks like 3dmark06 or Vantage is also inaccurate because most of those tests can withstand slight instability and not crash where as the same clocks, as before, will easily crash under <25 cycles of Crysis.

To be considered stable for me is to pass over 30 cycles in the Crysis benchmark because I have many OCed GPUs and played many games for 3 hours only to have them crash after 1 hour in Crysis. I actually install Crysis on every PC I plan to overclock the GPU/s, I may also run Arkham Asylum's bench just for variety.

Sorry to say but synthetic tests are never better than real life games. My 260m OC is that low because that was the best it could do under Crysis, which to me, crashes when it senses any instability. My bench is considered game stable and runs well for every game I play for hours on end. That to me is truly stable in every application.

Here's my log for when I OCed the 260m. Every little adjustment that lowered my frames per second was considered unstable by Crysis even if it finished all of its cycles. This was a shortened list, I spend hours on end to get my final OCed clocks...much to my fiancee's dissatisfaction for ignoring her...

[dttran83]

I don't have crysis anymore but can I use batman Arkham Asylum's instead? So you saiding if I run the benchmark test for 30 time without crashing then that mean it stable clock?

[Villosa]

Arkham works to a certain extent, it doesn't crash if it's unstable. During the game (but not during the benchmark) it'll artifact quite a bit though. Crysis will literally crash on you if it's unstable 98% of the time. That's the good thing about the game. It's the ultimate test in GPU strength and stability.

For normal users I don't recommend the way I do it unless you have a lot of time. I usually bench under Crysis for hours on end, cycle after cycle, that's like 2 hours without a computer to use. I also play a lot of games, Madden like 3 hours daily cause it's addicting followed by a bit of Mass Effect 2 maxed out with forced Vsync and 8x AA. When I buy a gaming system, I game the heck out of it lol. So basically I run stability while I game.

I run 30 cycles in Crysis to get preliminary stability and I work off of those to get ultimate gaming stability clocks. My current OC clocks have already proven to me to be my GPU's ultimate stability clocks, any higher and a game will eventually artifact and crash if played long enough. In real life that may not apply because why would someone play a game for 10 hours straight to wait for a crash? But to me, a perfectionist, the thought of it having the option of crashing is unacceptable.

I hope this helps.

[Mr Pras]

Regardkng stability my method is simple:

If there are no glitches or crashes then it's stable. If I can play the games I want for hours on end and there are no issues, then its stable. If I have a problem then I reduce the clocks.

At 700 I have not had any issue with any game except for throttling on GTAIV which I just play at 640..

You have to remember that most people are not overclocking it so it can be used by someone else in a commercial environment or as a science experiment.

I don't need to run 48 hours of burn in etc.. It's for me, and as long as all my games run perfectly, then it's stable.

Overclocking is to make games run better, at least that's what I use it for.

[Identifier]

I've been using Rivatuner to solve the throttling problem but I'm tired of always running at 550/1350/950 when just surfing the web. I thought that I might be able to solve the throttling problem directly on the BIOS by setting the 3D clocks to match the Extra clocks in NiBiTor (so both rows were 550/1350/950), but that immediately caused the video to crash with rainbow pixels all over the screen when booting Windows. I tried opening NiBiTor again and adjusting the 3D voltage to match the Extra voltage (1V) but that didn't help. I'm a bit confused why editing the 3D clocks in NiBiTor cause the card to crash at bootup. Has anyone else tried playing with the 3D clocks or voltage? (Not "Extra") I'm using NiBiTor 5.5, and I'm attaching the BIOSes just in case:

260M.ROM: Base image
260M1350.ROM: 3D clocks matching Extra clocks
260M135V.ROM: 3D clocks and voltage matching Extra clocks and voltage

[Mr Pras]

I've had the same problem when I change the 3D clocks (attempting to stop the throttling issue)..

I think it has something to do with Bootup clocks, but I decided not to delve too far in case I brick the card..

Perhaps someone with a backup GPU (dual GPU or SLI) would be willing to shed some light on it?

Here are three BIOS files that will help if you don't like editing BIOS yourself:

A05_current - Untouched
A05_640 - Base 3DPerf clocks increased to safe overclock of 640/1000/1600
A05_640+VMOD - Same but 3DPerf voltage increased for higher overclock (increased chance of throttling unless using a low power CPU)

[ninja2000]

I tried adjusting voltage on the extra (wanted to lower it slightly to lower heat and fan noise) but it also crashed on boot.

I will experiment some more but is there something we need to do after adjusting clocks or voltage or should just changing the settings and saving work?

[DR650SE]

My guess is that it causes the system to crash because the BIOS runs a hardware test. Same idea as the fan test upon BIOS post. Fans speeds up to full RPM to test. If it doesn't work, system shuts down to prevent damage.