HD 5450 or HD 5670?

[FlexiPack]

I'm looking for a dedicated GPU to go with the following spec

Asus P7H55D-M EVO
Core i3 550
4gb Kingston Hyperblue 1600mhz
Antec P180 Mini
Corsair VX450W

It's mainly for Photoshop, Lightroom with some very occasional video encoding. Currently I'm using the Integrated GPU on the Core i3 processor. I want a dedicated GPU but I'm unsure which to go for. I'm thinking either:

Sapphire HD 5450 512mb DDR3 - http://www.ebuyer.com/product/199429
--or--
Sapphire HD 5670 512mb GDDR5 - http://www.ebuyer.com/product/190138

1. The specs for both state a minimum of 500W - Surely my 450W PSU would be fine for both?

2. If I went for the HD 5670, I would want to replace the fan, can you recommend me a suitable quiet fan?

3. The HD 5450 is low profile, will that fit in my Antec P180 Mini?


thanks!

[dhanson865]

A 450W PSU will handle either card well and can even step up to the 5750 if you like.

I'd suggest you look at the stock fanless cards with a 5670 or 5750.

Gigiabyte has this one http://www.ebuyer.com/product/222268 but I usually look for powercolor cards here in the US.

newegg powercolor fanless list

I'm not sure were in the UK to find those cards.

Google UK price search for powercolor 5670 fanless

Google UK price search for powercolor 5750 green

Google UK price search for powercolor 5750 that isn't the go green version Cheaper but uses an extra few watts. Not the end of the world on power difference.

[Cerb]

AFAIK, neither PS nor LR have native uses for CUDA, which would be a reason to go nV (you'd still need to do some work to enable it on a non-Quadro, though). Just in case, I'd get a 1GB card, not 512MB. I don't know how much VRAM those apps need, but I do know LR can be GPU-heavy, and the added cost is minimal, while the performance hit from moving between video card and system RAM all the time would not be.

I'd go for a passive 5570 1GB, myself. If you're stuck needing the GPU, it will be a massive boost above the 5450, while not stretching your budget too much more. If 90GBP isn't a deal-breaker, though, a 5670 wouldn't be bad at all, giving you a good bit of performance headroom, and not much more heat. Without gaming, I think a 5750 would be quite overkill, regardless of cost (if you start needing better from pro apps than a 5670, it's time to look at FirePro and Quadro).