1156 vs AM3 system

The Core i5 750 system is definitely worth the price over a Phenom II 955 + AM3 motherboard if you intend to use more than one graphics card - the Phenom II 955 will hold back two HD 5850s in CrossFireX, and most AM3 motherboards have the 8x/8x limitation - on all CrossFireX ready AM3 motherboards except ones based on the 790FX chipset. Besides, the HD 5850 wouldn't need all 16x bandwith - 8x is more than enough. Once you overclock the i5 750, it will easily beat any Phenom II based system in gaming - and pretty much anything else too. As for a P55 motherboard with 8x/8x being expensive... no not really. Something like a Gigabyte P55A-UD4 would suffice.

Thanks for the reply  
Yeah i also noticed AM3 mobos have 8x 8x too.
So i guess i5 will be better..now..parts are more expensive where i live so thats why i say good p55's are expensive..

Hum what about the bandwidth issues of 1156...
Also in the long run AM3 will have six core support while the future of 1156 is unknown...

Bandwith issues? Regarding SATA III and USB 3.0? Then OP can get the ASUS P7P55D-E Pro or ASUS P7P55D Premium, which can handle the bandwith fine without any issues. If you meant PCI-e bandwith issues, then simply get a motherboard like the ASUS P7P55 WS Supercomputer with the NF200 chip, adding an extra PCI-e lane. As for upgradability - remember that LGA 1156 also has Core i7 Lynnfields, and the upcoming Thuban Phenom II X6 1000 series are meant to perform around at the same level, or faster than the Core i7 800s and 900s for multitasking. However, in the majority of applications which are either single or dual core threaded, the i7s will still beat the Phenom IIs, because Phenom II X6s are simply Phenom II X4 with two extra cores and an AMD version of Turbo Boost. How high the Turbo Boost will go - nobody's sure, but even with a Phenom II at 4.0GHz, an i7 800 at 3.46GHz (max turbo at stock speed, not overclocked at all) would still outperform it in the majority of applications, including most if not all games considering he's thinking of CrossFireX. Besides, gaming is his primary concern - most games don't use more than two cores, and I doubt they'd take advantage of six in a couple of years time.

Anytime you need a budget gaming system, consider AMD over Intel. Parts are more expensive when it comes to Intel, and AMD CPUs are much easier to overclock and have more headroom than the 1156 processors. Also, as the poster above said, the AM3 platform will support 6 core "Thuban" processors soon while the 1156 platform may become obsolete soon. Most importantly, when it comes to gaming, you should spend less money on the CPU and more money on the gfx card. That's why more ppl choose AMD when it comes to a budget gaming build.

Still the price premium for that chip on the 1156 motherboards cost a lot for someone on a budget. But your point about Thuban makes sense it always takes a few years for it to catch up. Also i tough 1156 was also X8 X8.

I have both of them, i5 and a Phenom II X2 555 unblocked into quad and both are very good. I'll keep the AMD though because I have a much newer mobo with USB3 and the latest AMD socket, I can overclock easily with the unlocked multiplier (not an OC nut and I can't stand fiddling with the RAM) and I'm waiting for the good Thuban stuff.

You can't go wrong with either one.

OP is not going for a budget build, as you can tell, because he is spending over $600 worth on graphics cards.
A Phenom II X4 will hold back two HD 5850s in CrossFireX. The article below shows the Phenom II X4 holding back two HD 5870s compared to an i7, which in terms of gaming performance, is around the same, and occasionally above or below the i5 750 in some titles.

http://www.legionhardware.com/articles_pages/radeon_hd_...

As for the price premium for the i7 on the 1156 - the AMD Phenom II X6 1090T is going to cost around the same, although probably a bit cheaper than the i7 860. It's not much of a price premium when they are assumed to perform around the same (860 and 1090T). Mind you, you can get i7s at MC for $200 - only $20 more than Phenom II X4 965s.

If he is spending that much why not just go 1366?

Also those 1156 even support X16 X16 Crossfire?