Hi guys Just wondering if anyone would be able to point me in the right direction for a new graphics..I havent bought a graphics card before and i know very little about them and i would be very grateful if someone could help...These are the specs of my computer
Compaq Presario sr1000 duo core
Microsoft Windows XP
Operating System: Windows XP Home Edition (5.1, Build 2600) Service
System Manufacturer: Compaq Presario 061
Processor: Intel(R) Pentium(R) D CPU 3.20GHz (2 CPUs)
Memory: 1984MB RAM
Psu 300watts max +12Volts 19 Amps
Card name: ATI RADEON XPRESS 200 Series
Manufacturer: ATI Technologies Inc.
Chip type: ATI Radeon Xpress Series (0x5A61)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_5A61&SUBSYS_2A3D103C&REV_00
Display Memory: 256.0 MB
Current Mode: 1024 x 768 (32 bit) (75Hz)
Monitor: Plug and Play Monitor
A computer is a closely woven system and parts depend on each other in order to work correctly.
The power subsystem is one thing that the video card depends upon, as you correctly identified. The cooling subsystem is another.
The same PSU with the same video card would potentially work very differently when put in two different computer cases with different cooling setups.
The wear and tear on the PSU also matters. It matters how old the PSU is and how it has been used throughout its lifetime. A new PSU of the exact same type might function very differently than a 5 year old PSU of that type even if it is in the same case.
Clearly there are a lot of variables involved and right now they aren't controlled ones. This model of PC came out about 2004 if I am not mistaken, that is about the closest I can get to controlling these variables right now.
Even with average usage, that PSU could be worn down to the point it will only put out 150w stable right now. The sort of video card I can suggest in light of that is quite different than the one I could suggest if the PSU were brand new.
Also, different PSUs use different quality parts. It is hard for me to know at this point how good the quality of the internal parts of that PSU ever were. OEMs like Compaq often skimp on PSU quality, so I can't assume they are really good ones that would have deteriorated more slowly than average.
Basically, what I am trying to say is that you may end up getting a new video card and becoming invested in it only to find that the old PSU is not good enough.
If that happens, you would need to spend about $45ish to get an Antec Earthwatts 430w or XFX 450w in order to get things going.
An aggressive answer would be to get a HD 6770 video card and a conservative answer would be to get a HD 6450. The more aggressive one would put you at a greater risk of the PSU not being good enough. Regardless which you get the risk would still be there, but with the 6770 it would be significantly higher.
Cards like a 6570 or 6670 would fall between those two extremes, conservatively and aggressively respectively.