Can't O/C x1600 memory with ATI TOOL!!

[colourmatch]

Every time I change the memory slider in ATI tool the screen goes gray and I have to hard reset? CPU O/C's fine, I have it on 470

I use a 20" imac with 256mb X1600

I see many others have higher speeds so whats the secret?
:confused: :confused:

[orbitalcomp]

Yeah, my 17" iMac is very sensitive to the memory slider, it seems. When I try and find the max speed for each thing individually, they both go up in the 500+ range, but if I set both at 470, the machine crashes...

Right now, I have mine at 400/400, and I have been running it like this for most of the afternoon. No problems, no artifacts...just ran the 1080p trailer for "Cars", and it was flawless. You might try yours at 400/400, it increased my fps from about 60 to about 85 in the 3D sample box.

Also, the temp doesn't seem any worse than usual...my default speed according to the ATITool was 313/300.

If I try to go to anything over 420/420, the machine crashes...I am also wondering how others are getting 470/470 or even higher. Maybe the MBP card is a bit different than the iMac...

[The Viking]

I'm no expert, but I wonder if the fact that my card is 256MB changes things. I can do 430/470 no problem, but I'm scared to push it any higher.

[diamondsw]

I see many others have higher speeds so whats the secret?

The secret is that overclocking is dangerous. Those parts were rated the speed they were for a reason. Some will run a bit faster, many won't. Your mileage may vary, and all that.

[webnome]

Your mileage will definitly vary depending on a number of factors. The method with the ATI tool is just trial and error. You may not be able to reach speeds others can.

[docbrody]

Every time I change the memory slider in ATI tool the screen goes gray and I have to hard reset? CPU O/C's fine, I have it on 470

I use a 20" imac with 256mb X1600

I see many others have higher speeds so whats the secret?
:confused: :confused:

are u using ati tools .24 or .25

try .25

[colourmatch]

Hmmm, My 20" iMac also has the 256mb, and yup using the .25 beta version.
I can take the gpu up to 470 no probs, I mean don't get me wrong I am more than happy with the performance anyway considering I never thought I would begetting two systems for the price of one:D

One point though is that my 256mb card was clocked at 398/396 to start with, would this mean that it could cope better with O/Cing as it was rated higher??

PC configuring, forgot all about it;)

[orbitalcomp]

Yeah, my 17" iMac is very sensitive to the memory slider, it seems. When I try and find the max speed for each thing individually, they both go up in the 500+ range, but if I set both at 470, the machine crashes...

Right now, I have mine at 400/400, and I have been running it like this for most of the afternoon. No problems, no artifacts...just ran the 1080p trailer for "Cars", and it was flawless. You might try yours at 400/400, it increased my fps from about 60 to about 85 in the 3D sample box.

Also, the temp doesn't seem any worse than usual...my default speed according to the ATITool was 313/300.

If I try to go to anything over 420/420, the machine crashes...I am also wondering how others are getting 470/470 or even higher. Maybe the MBP card is a bit different than the iMac...


After posting above and having trouble at higher speeds, I am now running at 470/470 with no problems. It definitely makes a difference to have the "carpet" box closed when making speed changes in ATITool.

Going from the default 313/300 to overclocked 470/470, the difference is noticeable in just overall system responsiveness, web browsing, etc. My SlingPlayer seems to run much smoother, as well...