I'm using CS4 Extended and for some reason the GPU Accelleration is now no longer available, The only thing I have done is to update my Video Card Drivers that I can think of, but I would Ideally want to keep the latest version of drivers installed because I use this machine for playing PC games too.

Has anyone else had this problem in CS4?

http://kb.adobe.com/selfservice/viewContent.do?externalId=kb404898

On this page you will find this:

1. Perform additional troubleshooting.

It gives you two extra plug-ins that open psd GPU accelleration. It could help you

Thank you very much will have a look.

When I first got PSD CS4 my card the GPU Acceleration was not available. PSD CS4 did not even see my card (ATI X800). The plug-in for Win32 made my card visible but it was not strong enough, I had to change it...

I came in here myself for this answer. I am using a 9800GT with 1G onboard RAM and 4 G system memory...more than adequate but i get the same thing...No GPU support for me either.

I'm sure this must be a video card driver thing or something because it worked for me once I installed CS4, since then, updating my video card driver and it's no longer available.
I'm not too confident installing the 3rd party plugins for the GPU as it's not supported by Adobe (being the main reason), but because I know it works, it's ust for some reason CS4 now wants to be picky as to which video card driver is installed. and I'd rather not rollback my driver (though I may have to) to get GPU to work if I can still use CS4 without it, I really wanted to be able to use the rotate view tool though.

Chodo121 on the link I gave there is something ( I beleive ) on the 9800GT card.

Eagle Wing 1000 I installed the plug-in on my system and had no trouble.

Quote - Eagle Wing 1000 I installed the plug-in on my system and had no trouble.

Cool, so GPU works fine after you installed it? ok. thanks, I will give it a go then. thanks.

http://kb.adobe.com/selfservice/viewContent.do?externalId=kb404898

This will help as GPU is turned off by default and needs the card to be enabled

That plugin works great.

Thanks.

What sort of performances are you guys noticing when using GPU acceleration?

For most people, with up to a 12-megapixel  or doing Web design work, the difference you will see is pretty negligible.  It has been suggested that the inflection point from 32-bit to 64-bit  happens where you would have run out of memory and would have had to go to your virtual memory system, storing data on the hard drive rather than in memory. So this is where  I would suggest you will now find  a tenfold performance increase opening up a large file. And also when you magnify the image the pixels remain sharp and does so with remarkable smoothness.