GDDR2 GPU with DDR3 mobo? Advice pls

[DennisMenace]

I've recently bought a new i3/DDR3 PC (from here, of course!), a Primo Ignition :
http://www.overclockers.co.uk/showproduct.php?prodid=FS-270-OK&groupid=43&catid=1078&subcat=
which has adequate onboard graphics for my needs (ie NOT gaming). The only limitation is the lack of DVI/HDMI, as I am aiming to upgrade my 19" VGA to a 22-24" widescreen LCD/LED monitor.

Hence I need a (cheap) graphics card to get a digital connexion, and something that won't strain the 450W PSU. I was considering a XFX ATI Radeon HD 5570 1024MB DDR2 PCI-E as it is "energy efficient & low-profile", but could this actually REDUCE performance? (It has 1000MHz DDR2 versus 1333Mhz DDR3 system memory).

Also, could anyone suggest a more suitable card? It has to be :
1. Cheap (<£75-ish)
2. Low power
3. DVI & HDMI
4. Preferably DX11
Alternatively, would I be better to wait until I can get a "half-decent" card, eg GTX 460 or HD 5770 (if my PSU would support them), as they become cheaper?
As I said, I'm not a serious gamer, although I would like to play a few (eg Fallout 3/NV, DAO) and will be using my new monitor for BD/1080p playback. Any ideas/suggestions appreciated.

 

[DennisMenace]

Thanks a lot for the advice (wise)guys.

Looks like I might have to start saving up for a better GPU - my original plan was to get a super-cheap card (£30-ish) just to get HDMI, but I'm still not sure if this could reduce performance.

Also, it's hard to find exact data on power usage, as a 450W PSU doesn't give me a lot of leeway. Generally, are ATI or Nvidia lower power??

My first priority is to get a decent monitor - if I can make a saving on that, I could have enough to get a half-decent card too. (And if I can spam like crazy for 3 months, I'll get the free shipping too!). Guess I'll keep a close eye on those "this week only"/"today only" deals and hope for something suitable...