Ditch my E6600 for a new Phenom II x2 550 BE?

I have owned my current rig for a few years and I have some money to spend on a small upgrade and I was wondering if now would be a good time to do it? I am having a difficult time finding some performance ratings of the Intel E6600 vs Phenom ii x2 550 BE.

Current rig:
Core 2 Duo E6600 (OC to 3.1GHz) (upgrade)
4GB Corsair Dominator PC1066 DDR2 (upgrade)
DFI Lanparty 975X/G MB (upgrade)
EVGA 8800GTS 320MB KO (upgrade)
Twin WD Raptors in RAID-0 (keep these)
Corsair HX620 PSU (keep this)
Windows 7 Ultimate 64bit

Future Rig:
Phenom ii x2 550BE (unlock and OC to 3.6GHz QUAD)
Xigmatek Dark Knight 120mm CPU Cooler
Gigabyte GA-MA790XT-UD4P
8GB G.Skill DDR3 1600
XFX HD5770 1GB (eventually buy a second to run crossfire)
Transfer WD Raptors from old pc
Transfer Corsair HX620 PSU from old pc.
Windows 7 Ultimate 64bit

Total cost is around $600.00 to add the new proc, hsf, mobo, memory and vid.
Would I see a significant increase in performance? I do a lot of photography and work in Lightroom and I'm a gamer and play COD4/COD6. I only do FPS games.

My other option would be to keep my Intel system and simply upgrade the video card to the XFX HD5770 for about $180 shipped. Upgrade the cpu/mobo next year early spring.

Thoughts and comments? If there is a significant performance increase on my proposed system vs existing system, for the minimal cost i may jump on it, if it's only my GPU lagging, i'll just upgrade the vid card. What do you experts say?

Thanks!
Eric

First of all you can't really count on being able to unlock the extra cores on the 550BE. It really is a hit or miss. Also, even if you do manage to unlock them you will have a lower stable overclock speed and will probably have to use a higher vcore. I say update your BIOS, upgrade to a Core2 Quad, overclock said quad, and put in two 5770s to run in crossfire.

A C2Q will cost too much for such an upgrade... You can get an x2 620/630 and a decent mobo (AM2+/AM3) for less than C2Q alone . With the money saved you can get dual 5770's ......

I would also recycle your Corsair 1066Mhz, spending 180.00$ on that Ram is not going to justify the performance.

The reason I would not go with LGA 775 is basically due to having to upgrade sooner than later. That socket has it's days counted....

Hope this helps....

First offf, do you have a Microcenter near you? They offer the Q9550 159.99 . That price I would upgrade . For the 260 that online etailers charge you could get a 955be/motherboard combo new.
http://microcenter.com/search/sear [...] tegory=HB3

^^ and that is at stock speeds, if you overclock that 620/630 around the 3.2Ghz mark you will get basically the same frames as a 955 stock. Well the 955 might get a few more frames but nothing to worry about.... The x4 620/630 is a superb CPU for the money.... Best bang for buck ATM....

Personally, I think you'd be better off getting the graphics upgrade now (maybe adding another two gigs of ram while your at it) and wait for the whole system rebuild until next year. I9s and AMD 6-cores should be out by then, which means the current top of the line cpus should be significantly cheaper, and your current OC on your cpu makes it still competitive. Most games don't take advantage of more than two cores anyway, so you'll see more of a benefit by putting all the money towards an HD5850/70.

The L3 helps in games among other apps, not really needed if you want to justify the price between both CPU's. I have seen a 620 overclocked to 3.4Ghz vs. a 965 (stock) and the performance difference was around 5-6%, nothing mind-blowing....

wow... you got a heck of a deal there =)

He got a 965 for the price of a 550

does not get any sweeter than that......