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We have 40 different Intel e5420 "cores" spread across eight rack machines. These machines are about five years old. The application is scientific computing, specifically a kind of single threaded Monte-Carlo simulation.

When we move to a new office very soon, we would like to replace all these machines with a single one (or two). I strongly suspect a single machine like this HP ProLiant DL585 is much more than twice as powerful as the current setup, but I don't really know how to cook up a back-of-the-envelope comparison. I'd like to be able to announce: It will be about 3.2 times as fast. The example HP machine has four AMD Opteron 6300 Series Processors.

I understand comparing CPUs (and mainboards) can't necessarily be reduced to a one metric apples-to-apples thing due to various differing characteristics, but what's a good rule of thumb? How could I do the math with readily available information to make sure some machine I buy is at least as powerful as 40 Intel e5420 cores?

More specifically, anyone got any server recommendations? We're looking to spend about $10K for as much CPU power in a single machine as possible. It'd have to run on a 110V line.

TIA.

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Product recommendations are specifically not allowed, I suggest you remove that part to avoid your question being closed. – mgorven Jan 31 at 21:02
It's quite obviously not in any shape or form a recommendation. It is a specific example that clarifies. – tjrjr Jan 31 at 21:03
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"More specifically, anyone got any server recommendations?" That looks very much like a recommendation request to me. – mgorven Jan 31 at 21:04
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Contact your reseller to find out if you can lease a server on a short-term (e.g. 1 month) basis. Then you can benchmark it yourself. – Michael Hampton Jan 31 at 21:50

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2 Answers

up vote 0 down vote

Your old machines are very much outdated... You are asking for a recommendation, though...

Look up the PassMark CPU benchmarks for relative comparisons. http://www.cpubenchmark.net/

The HP ProLiant DL585 G7 you posted is a dog. It's not a very popular unit, and it's a bit of a White Elephant. That platform is really no good for the cost/performance/practical uses.

You'll find much better value in a modern 300-series Intel system - For example, an HP ProLiant DL380p Gen8.

But more than anything, this depends heavily on your application and computational needs. You can probably consolidate onto two systems, but we can't tell you how things will perform. You'll have to test and benchmark on your own.

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So two Xeon E5-2665 processors means 32 "slots" run our simulation process, if I understand correctly. What's a roughly reasonable way to compare that to what we have now? I can certainly run benchmarks on the current gear, but I can't benchmark new stuff without buying it first. – tjrjr Jan 31 at 21:19
People do evaluate equipment without buying it... But yes, you'd be moving ahead three generations in server and processing technology. Look at an E5-2690 CPU-equipped server for maximum single-threaded performance. – ewwhite Jan 31 at 21:25
I still have no idea how to figure out roughly how much faster I can expect a single threaded process running on a E5-2665 to complete than on a e5420. That's the essence of the question. Can I divide one CPU Mark score from cpubenchmark.net by the other? – tjrjr Jan 31 at 21:49
@tjrjr no you can't. The numbers are weighted benchmark results which likely would not reflect the load induced by your simulation. The numbers are typically only any good for general-purpose-applications, if you have specific needs (like fast integer calculations or floating point double-precision calculations), you are better off looking for more discrete benchmark results as the ones offered by Spec. You still would have to know which of the available benchmarks fits your use case best. – syneticon-dj Feb 1 at 8:34
@ewwhite why is the 585 G7 a White Elephant? It's just another 4-way Opteron machine, isn't it? (AFAICS HP does not have any 4-way Opteron machines but this one). – syneticon-dj Feb 1 at 8:40
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up vote 0 down vote

It mostly depends on the workload, anyway other than updating the hardware I would suggest you into seriously considering GPU computing. Most problems that I'm aware of can get a performance boost by only using the appropriate library (and there are plenty of OpenCL/CUDA showcases).

As per your question, product recommendations are not allowed, but start into looking at a CPU that has a high operation frequency and some serious amount of cache (high end Intel and AMD). If your problems can benefit by libraries like OpenMP then look for the highest amount of cores (I believe AMD will win in this section) and enjoy the benefit of parallel computation, otherwise pick the highest operative frequency (probably an Intel) for single threaded stuff.

As per the products for Dell servers you should look into: R820/R920 as these are the only 4 socket machines that I'm aware of made by Dell, for HP the DL 560 and above (maybe limited by your budget) should be good enough.

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The simulation in question cannot benefit from SIMD. That's a red herring in the case. – tjrjr Jan 31 at 21:51
Then the answer to your question rely on simply getting a sample machine (if you call the sales representative from HP or DELL they will probably get you one in case the opportunity is big enough) and measure the performance difference by executing the code. – Martino Dino Jan 31 at 21:57
And if you want the best ratio between performance/price don't buy high end machines and CPUs. As an example from Dell you can get a fairly decent deal for the 1U 2Socket R620. – Martino Dino Jan 31 at 21:58

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