I’m looking to upgrade my CPU to handle 5-boxing. I currently have an old Core2Duo E6300 (1.83GHz Dual-Core). I can handle triple boxing all right, but that pretty much pegs out my CPU.

So I started looking at upgrades. I’m hoping to keep my existing motherboard, but that does limit me to the Core2Duo/Core2Quad lineup – no i7 ?.

I’d like to be able to bring 5 toons through Dalaran without coming to a screeching halt. I know the old recommendation was that you needed about 1.5 GHz for your main, 1 GHz per slave and at least 500MHz for the OS. (i.e. a dual-core 2GHz CPU would cap out at 3-boxing, 1.5+1+1+.5 = 4).

But I think that was before WOLK and Vista came out. Now I think it’s looking more like double that. That would put a good 5-box set-up requiring 3+2+2+2+2+1 = 12GHz of processing power if we want to Raid and WG with them all. Sound about right?

Without getting into the low power CPU’s – I see 6 quad-cores on Newegg that I can run.

Q8200 – 2.33GHz, 4MB L2 Cache - $160
Q6600 – 2.4GHz, 2x4MB L2 Cache - $200
Q8300 – 2.50GHz, 4MB L2 Cache - $170
Q8400 – 2.66GHz, 4MB L2 Cache - $170
Q9400 – 2.66GHz, 6MB L2 Cache - $190
Q9550 – 2.83GHz, 12MB L2 Cache - $220
Q9650 – 3.00GHz, 12MB L2 Cache - $320

The price jump from Q9550 to Q9650 seems pretty steep. For that matter, is it worth $50 to go from a Q8400 to the Q9550? I’ll probably try to OC any of them at least a little bit, so I’m mainly looking at a difference in the amount of L2 cache and I have no idea how cache intensive WoW is.

Thoughts?