Considering SLI

For optimum operations of SLI, you should get another GTX570 with 2.5GB RAM, shader and clock speed as same as the EVGA card you own. The speed can usually be adjusted in any card by overclocking.

If you dont meet these criteria, you TWO cards will perform roughly twice the performance of the LOWEST spec'd card. Eg: if you pari a 2.5GB with 1.25GB card, your SLI will operate at 1.25GB.

technically, you can SLI with another 570 regardless of specs like ram. just make sure its a 570 gpu.

vram will be the problem...

+1

If you get a "standard" GTX570 with 1.25Gb of VRAM, your SLI rig will only use 1.25Gb.

Otherwise, an SLI rig will scale quite well, but not x2.

So if i got a EVGA gtx 580 with 3gb on am i correct in assuming it will scale to my current card to 2.5gb?

you can't run a gtx 580 with a gtx 570 in sli.

i was under the impression same series as in 5xx same GTX?

nope won't work, you can only sli the same card. So 570 with 570, not 570 with 580.

No mate, that's an ATI feature, you can pair any 5xxx or 6xxx series cards, but to be honest it's fairly pointless since the pair will run at the lower clocks of the two cards.

well i am indeed out of options it seems, there no good 2.5gb 570 from companies i trust.

Which companies do you not trust?

You can't find another EVGA with the 2.5 vram?

Right here: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

im in the uk. there non longer available from big retailer like scan.co.uk.

companies i dont trust like unknowns like Point of View and Palit. And others that have failed me like Gainward.
to name a few.

Names i trust would be: Asus, EVGA, Gigabyte and XFX (used to be good unsure these days)

Get it from Amazon

http://www.amazon.co.uk/EVGA-025-P3-1579-KR-GeForce-Gra...

its out of stock, its out of stock everywhere.

Make a pre order, from other sites says there is a delay in re stock

Another option is to get it from ebay , I know its not the best option , but just an idea depending how desperately you need the card.

http://www.ebay.co.uk/itm/EVGA-NVIDIA-GEFORCE-GTX-570-2...