The concept of a usb stick giving you a significant boost in performance is LOL.
Actually turbocaching would work.
It doesnt give you a 'boost in performance', what it does is store background crap which frees up more of the system ram.
In terms of performance using caching:
- 4 Gb system ram + turbocache will give you the lowest gains, but will free up your 4 Gb for your more demanding programs
- Upgrading to 8-12 Gb will be even better as direct system ram for caching is much faster than turbo boost
- Upgrading your Vram will be even better still, as graphics data caching in the Vram is even faster than caching in system ram.
Actually, those three points are perfectly arranged by cost and performance gain. ATM if you already have a fast graphics setup with 1 Gb Vram (5850 / 5870 / GTX 460 / GTX 560 ti in Xfire / SLI), but only 4 Gb ram, upgrading your ram will give you the most cost effective upgrade.
If you are using really old graphics cards and looking to upgrade, buying cards with more Vram (1.5-2 Gb) will give you some extra Vram for graphics caching.
However, you simply wont be able to get as much room for Caching in the Vram as you can get with cheapo system ram - a 3 gb GTX 580 is extremely expensive, and paying so much money for this card s ridiculous.
However, 2 Gb GTX 560 tis, or 2 Gb 6950s are very attractive buys at their price point and worth buying now if getting new cards. However users with 1 Gb Vram and 8-12 Gb system ram are going to have the same benefit with shared ram, but just slightly slower than having more Vram.
Upgrading from 1 Gb 5850s or GTX 460s and higher just to get more Vram, expecialy if you have two of them is a ridiculously bad move as it will be a lot better to wait for the next gen with such setups. Just add more system ram and wait for HD 7000s / Keplers before upgrading to faster cards with 2 Gb Vram.
I also just 'downgraded' my 24 Gb cas 9 1600 Mhz ram, to 12 Gb Cas 7 1866 Mhz ram:
I didnt buy any new ram, just went back to my speedy 2 Gb sticks that I was using before the 24 Gb upgrade as I dont need more than 12 Gb, and this stuff is a lot faster which actually does improve min FPS by about 2-4 in several games (about the same benefit as going from 1 Gb to 2 Gb Vram).
But theres really no point in buying faster ram if upgrading because it costs too much more for a very slight increase, unless you are looking to build the absolute highest performance you can get, in which case loads of superfast ram (those new X79 quad kits are super yummy), and more Vram combined would actually give you a significant, but hardly cost worthy performance boost. Mine are just the Geil Ultra OEM sticks that OCUK had for £70 per 4 Gb ages ago, and I'd rather use those than slower 4 Gb sticks.
. I have another option: keep it until I upgrade 
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