Would a new graphics card be worth it?

I have a P4 2.66 cpu, 1 gig of ram and a Radeon 9800 pro 128 bit.
My question is; would it be really worth my while in getting a new graphics card (AGP) or will my cpu throttle it? I have a budget of £500. tops.

No

If I were you I'd use that to start saving and get a new rig. It just wouldn't be worth your while getting a new graphics card if it has to be AGP, you'd probably need to get a new psu as well and I reckon your cpu would "throttle it" to steal a phrase. Of course, it's up to you...

Keep your RAM and Graphics card and buy a new motherboard and CPU.

Then save up for a new graphics card.

While I agree with the two previous replies if you really just want to upgrade your graphics card and can find a good deal on a x800 pro or x850 pro you will see a decent performance improvement in going to a 256 bit memory interface from the 128 bit not to mention the faster clock speeds and the 12 pixel pipelines over the 8 pixel pipelines in the 9800. but it really isnt worthwhile unless you can find a good deal on the card.

Thanks folks; in the end i got a gforce 6800gs from xfx and 1 gig of ram. I have noticed some artifacts from the gforce card; any ideas why? And i haven't overclocked it. I have 480watt psu.

Artifacts can be caused by several things. the card overheating is one, how is your case ventilation? or a defective card. are you running the latest drivers for the card?

It's weird; it only seems to affect certain games. FarCry/ TRlegend there was but Quake 4 / splinter cell chaos theory there was none. Which makes me wonder if it's the drivers?

If it is only happening in certain games then it sounds like it could be a problem with the drivers. BTW did you uninstall the ATI drivers before installing the Nvidia card?

Yes i did uninstall the radeon drivers and i have even tried uninstalling the Nvidia drivers and replacing them with earlier versions; but still the same results.

The thing which is going through my head is that the XFX card is already an overclocked 6800gs out of the box and i'm wondering if they have overclocked it too far?

You might want to contact XFX customer support and see what they have to say about the problem.

Contacted them; still waiting for a reply though.