Nehalem vs Westmere better for Cloud Computing??

[Roger_H_Intel]

My understanding is that the Xeon 5600 series is more appropriate for cloud computing than the Xeon 7500 series, but Im not sure why. It seems that the larger headroom of the 7500 series would make it the better choice, although maybe the choice is driven at least in part by performance per watt?

[Tw_Burger]

My understanding is that the Xeon 7500 has a 2.2x overall performance advantage over the Xeon 5600 series. The 5600 series has up to 6 cores and 12 threads and the 7500 up to 8 cores and 16 threads per processor:

INTEL XEON PROCESSOR 5600 AND 7500 SERIES FEATURES
	XEON 5600 SERIES	XEON 7500 SERIES
Code Name	Westmere-EP	Nehalem-EX
Max. Cores / Threads	6 / 12	8 / 16
Max. L3Cache	12 MB	24 MB
Core Frequency	3.33 GHz	2.26 GHz
Processor Socket Scalability	2	28+
DDR3 Memory (Slots/GB per socket)	9 / 144	16 / 256
Reliability Features	Standard	MCA Recovery
Process	32 nm	45 nm

So, which is more appropriate for cloud computing? It depends on what the application is rather than a straight 'Which is better for Cloud Computing? choice or a subjective performance per watt rating. From what I can see the series are similar in design except for more advanced features and raw parallel processing power in the 7500 and better per thread performance of the 5600. I have to conclude that the choice between the two is going to be based mainly on the capacity/scalability with the 7500 targeted for high performance markets.

The 45nm Xeon 7500 series is an eight core processor with hyper-threading and turbo boost, and a 24MB (shared) L3 cache, and to 16 memory slots per socket. A system with 64 logical cores and a 1TB of RAM in a four socket server would cost around $100K (for example a Dell PowerEdge R910 based on maximizing of the CPU and memory options). The advantage of this system is memory bandwidth and scalability.

A two socket 32nm Xeon 5600 series processor system would have 24 logical cores and up to 288GB of RAM and cost about $30K. This system, with 32nm Westmere technology would certainly have a potential advantage of better transactional performance with individual thread processing speed being better than the Xeon 7500 and greater system power savings.

[Hussam_Mousa__Intel_]

Nehalem EX (Xeon 7500) is an MP system, usually running with 4 sockets or more. It will be a huge feat to saturate such a system and keep it busy enough to stay in the performance per watt sweet spot.

Westmere EP (Xeon 5600) is a Dual Processor system and even through core to core is a tad more powerful than the Nehalem EX core, as a system I can see it as being more practical and flexible for a cloud computing infrastucture.

First, it wouldn't take as much to have it running in its performance per watt sweet spot so it will stay efficient in those slow hours. Second you can have several of them deployed, load balancing each other and giving you plenty of room for a "surge" in case your cloud utilization jumps up suddenly. Third they canwatch each other's back (High Availability, Fault Tolerance, etc...).

Not to suggest NHM EX isn't right for cloud, but it will ultimately come down to exactly how big and heavy and utilized said cloud is.

Cost wise, going with 2 DP systems may eventually offer more flexibility, but there are people who do Data Center sizing for a living, and I am not one of them, so this is just an educated guess.

(this is obviously my personal opinion and nothing more)