Time for a new processor and memory me thinks
and motherboard..either way, not going to be under £150 methinks

Time for a new processor and memory me thinks
What's a 'pretty average/rubbishy spec PC' ?
Care to post a screen of the settings menu?
You want more than half a gig of video memory sorry. GTA4 is very hungry on VRAM.
I have a pretty average/rubbishy spec PC, but I play this fine 1680 x 1050 with all settings up as far as the game allows... I don't get everyone saying runs like ****
I hate SLi,, EVIL and a total waste of money. Or it was back in the nvidia 6800 series days and I will never ever have another SLi system as long as I live
Can't post a screenie as I'm away from home for the week... Spec is Q8300@stock, 4gb DDR2 800mhz ram, 8800gt 512mb. The settings are basically all dragged up to as far as the game will allow (it seems to prohibit them being dragged all the way up, I guess it auto-restricts dependent upon hardware)
Statistics
Average FPS: 26.90
Duration: 37.48 sec
CPU Usage: 93%
System memory usage: 68%
Video memory usage: 73%
Graphics Settings
Video Mode: 1360 x 768 (60 Hz)
Texture Quality: High
Texture Filter Quality: High
View Distance: 26
Detail Distance: 51
Hardware
Microsoft® Windows Vista" Home Premium
Service Pack 2
Video Adapter: ATI Radeon HD 5800 Series
Video Driver version: 8.14.1.6095
Audio Adapter: Speakers (Realtek High Definition Audio)
Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz
funnily enough it would be cheaper to buy an xbox 360 arcade and the 360 game than to buy a quad core CPU for your PC
I'd just like to say, this is one of the BEST games I have ever played in my entire life. Performance is excellent for me at max settings. Graphics are absolutely beautiful. It's an extremely well designed, produced and coded game imo.
I am always dumbfounded and left with my face in my palm when someone farts out a statement like "It's poorly coded", "its a crap port", "it's better on consoles", etc..
This game is a complete masterpiece, I've played through it over 3 times now and never get bored of it.
Bad console portit is not
Well it looks and run like ass. (not on my PC, my i5 brute forces its way through it)