Overclocking Phenom 9550- is this safe?

[JumBie]

The stock clock speed is 2.2ghz on this CPU. Can I overclock it by just making a change to the FSB and leaving the multiplier at 11, and the voltage untouched? I currently changed the FSB to 210 and its running @ 2.31ghz, I want to push for more, but not sure whether or not I have to make changes to the memory or voltage.

 

[Deders]

If it starts to be come unstable, raise the voltage until it is stable.

 

[JumBie]

If it starts to be come unstable, raise the voltage until it is stable.

Sounds good, I have it @ 2.4ghz right now at 220 fsb. If ill keep bumping it slowly until i see instability then ill bump up the voltage.

 

[JumBie]

Looks like something is wrong, testing it out in a game of league my fps is lower than before. Its not chugging or lagging at all, but the overall fps is much lower than before, its gone from a stable 60fps to 45-55fps.

 

[SlowSpyder]

When you overclock by FSB, you're also raising your memory speed. unless you set a different divider. Could be your memory crapping out, I'd drop it back to 210-215 and then see about using the multiplier.

 

[2is]

Looks like something is wrong, testing it out in a game of league my fps is lower than before. Its not chugging or lagging at all, but the overall fps is much lower than before, its gone from a stable 60fps to 45-55fps.

This isn't uncommon when you're on the verge of instability. The CPU is having to processes instructions multiple times due to errors, this causes a performance drop. Could be due to memory or CPU. Personally, when overlocking, I like to keep my RAM as close to default speeds as possible. Once I get my CPU speed to where I want it (stable) with acceptable temps, I'll then turn my attention to RAM... (maybe)

 

[VirtualLarry]

This isn't uncommon when you're on the verge of instability. The CPU is having to processes instructions multiple times due to errors, this causes a performance drop.

Just a note - this is only true with GDDR5 memory, because of the error-correction in the communication protocols.

In CPUs, there is no "error = retry" feature. (*)

(*) Some claim that there is some sort of feature like this in Sandy Bridge and newer CPUs. This seems unlikely to me, because the CPU would have to calculate the result twice, either sequentially, or in parallel, in order to check results. This would be a massive waste of CPU resources.

 

[JumBie]

This isn't uncommon when you're on the verge of instability. The CPU is having to processes instructions multiple times due to errors, this causes a performance drop. Could be due to memory or CPU. Personally, when overlocking, I like to keep my RAM as close to default speeds as possible. Once I get my CPU speed to where I want it (stable) with acceptable temps, I'll then turn my attention to RAM... (maybe)

Please walk me through what I may need to do. Even overclocking to 2.3ghz I am getting stuttering in games. And thats just upping the fsb to 210, from 200. Any help would be greatly appreciated.

 

[2is]

Just a note - this is only true with GDDR5 memory, because of the error-correction in the communication protocols.

In CPUs, there is no "error = retry" feature. (*)

(*) Some claim that there is some sort of feature like this in Sandy Bridge and newer CPUs. This seems unlikely to me, because the CPU would have to calculate the result twice, either sequentially, or in parallel, in order to check results. This would be a massive waste of CPU resources.

I'm not engineer, so I can't say with 100% certainty, what I can say though is I wouldn't think checking for errors is a waste of resources personally. Another thing I can tell you when I'm overclocking and use IBT to stress test, I know exactly when I'm on the verge of failure and that's when my next OC bump yields in no gains or even a slight loss in gflops, even if it makes it through the test. Sure enough, another MHz or two on the base clock throws an error on the subsequent run.

Please walk me through what I may need to do. Even overclocking to 2.3ghz I am getting stuttering in games. And thats just upping the fsb to 210, from 200. Any help would be greatly appreciated.

First we need to establish that your stuttering is due to your overclock. Do you only get stuttering when attempting to overclock or does it happen when everything is at default settings too? I know you said you got 60 before and 45-55 now but that's not at all a scientific measure if all you did was go into a random game and looked at your fraps counter. This is one area where a static benchmark is helpful. If you have a game with a built-in benchmark mode, use that. If you don't, use something like heaven, but lower the graphics setting to minimum, or better yet, cinebench. These will be repeatable tests and if you are in fact losing performance when overclocking, it will show up in these tests.

 

[JumBie]

I'm not engineer, so I can't say with 100% certainty, what I can say though is I wouldn't think checking for errors is a waste of resources personally. Another thing I can tell you when I'm overclocking and use IBT to stress test, I know exactly when I'm on the verge of failure and that's when my next OC bump yields in no gains or even a slight loss in gflops, even if it makes it through the test. Sure enough, another MHz or two on the base clock throws an error on the subsequent run.



First we need to establish that your stuttering is due to your overclock. Do you only get stuttering when attempting to overclock or does it happen when everything is at default settings too? I know you said you got 60 before and 45-55 now but that's not at all a scientific measure if all you did was go into a random game and looked at your fraps counter. This is one area where a static benchmark is helpful. If you have a game with a built-in benchmark mode, use that. If you don't, use something like heaven, but lower the graphics setting to minimum, or better yet, cinebench. These will be repeatable tests and if you are in fact losing performance when overclocking, it will show up in these tests.

Cinebench score stock 2.2ghz - 208.
Cinebench score oc FSB 220 2.4ghz - 205.

The stuttering only seems to be happening when I overclock.

UNIGINE WITH OC 2.4ghz

FPS:
38.7

Score:
975

Min FPS:
8.4

Max FPS:
63.7

UNIGINE WITHOUT OC 2.2ghz

FPS:
42.6

Score:
1072

Min FPS:
14.4

Max FPS:
69.4

 

[BUnit1701]

Step 1 when overclocking via FSB is to lower your memory divider by one step to ensure you are not causing memory errors. So, if you have DDR2-800, set for DDR2-666 (from 400Mhz to 333Mhz). Also, you may want to lower your HyperTransport(HT) Multi by one, most AMD boards respond very poorly to an overclocked HT.

 

[2is]

Step 1 when overclocking via FSB is to lower your memory divider by one step to ensure you are not causing memory errors. So, if you have DDR2-800, set for DDR2-666 (from 400Mhz to 333Mhz). Also, you may want to lower your HyperTransport(HT) Multi by one, most AMD boards respond very poorly to an overclocked HT.

Yep, start here... If that fixes the stuttering issues, then start increasing FSB (and voltage as necessary) until your RAM is back up to it's rated speed. That should yield in a decent overclock without also OCing the RAM