What part of my computer should i upgrade first?

Hello. The subject/title says it all what should I upgrade first in my computer? I'm wanting to do SLI with another EVGA GTX 670 FTW but my motherboard doesn't support it. Even if it did the second slot is taken by the wireless card. I'm not sure if i should go with a new motherboard first or graphics card. No real specific budget just keep things reasonable. I hope this is enough information if it isn't I can add links later. I posted this from my tablet.

CPU: I5-3570K @3.4Ghz


GPU: EVGA GTX 670 FTW. For the most part it's not overclocked but I'm starting to look into that with PrecisionX.



SSD: OCZ VERTEX PLUS 60GB. Used for the operating system. Cutting it close I know but I never let it get full.

HDD: 1TB Western Digital Blue @7200RPM 64MB cache

Operating system: Windows 7 Home Premium.

RAM: G.SKILL SNIPER SERIES 8GB (2×4GB) @1866. Pretty sure my motherboard down clocked it to 1600. I've ordered a pair of CORSAIR VENGEANCE LP 16GB (2×8GB) @1600. They've already shipped.

Case: Zalman Z9.

Wireless networking card: ASUS PCE-AC68 PCI express dual band. My motherboard doesn't have a PCIE slot for it so I ended up putting it in the second slot for a graphics card.

Is the GTX 670 the 2GB one?

Yes it is.

We'll if SLI ident a option I would say go for. Better single card like the R9 290x/gtx780

I'd say this build is fine for another 1-2 years before upgrading anything.

But if you feel you need to upgrade anything, I would say a bigger SSD or another HDD.