This system they're testing is a beast that's designed for enterprise systems; they're hugely expensive. You're meant to get perhaps 144 hardware threads, hundreds of gigabytes of RAM, terabytes of storage and a price tag of >$50,000; it's designed for the limits of vertical scaling (and is a job I imagine it does well).

Even if you were to dump this kind of cash, you'd get terrible performance in practice due to the design decisions made behind all of this (memory system will be tuned for throughput not latency, for example) and poor software support (i.e. an OS like OS X would do a shoddy job of scheduling threads, especially across NUMA domains. Linux was terrible also until a few years ago, it wouldn't manage to schedule more than about 30 threads simultaneously no matter the lad).

I'd go so far as to say that you'd expect better performance from a standard tower than you would from this.

In general you'd expect a desktop processor to give you about as good performance as you'd manage to get for developing C++. All of the editing tools are tuned for desktop processors, and there's not amazing parallelism to be had with most compilations (and incremental compilations won't see them at all). Note the benchmarks are for 'total number of kernel compilations' and not 'time for single compilation' :)

I regularly run 'make -j32' on a machine, compilation of well-structured projects is embarrassingly parallel. Incremental compilation is a fair point, but may not always work in template-heavy codebases that are restricted to C++03 (no extern template).

I'd say that normally, you probably don't need it, unless you want ECC memory, large cache sizes, large amounts of memory, etc. (compared to Core i7)

However, they can be very price-effective. Many companies buy workstations for e.g. CAD and replace their machines every 2 or 3 years. Since they are then sold en masse on eBay, you basically get a machine that is still high-end for a bargain price.

E.g., my Xeon workstation was ~400 Euro, has a Xeon E3-1270 that is ~4 times more powerful than my relatively new Mac Mini, comes with an acceptable CUDA-capable GPU, and 12GB memory.

If I was to buy a new CPU today, I'd buy this one:

https://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-5930K...

I also have quad channel OC memory on my motherboard, the quad channel part is actually significant in terms of compile speed (and the OC part isn't I found out.)

Depends on the kind of number crunching. If you are doing expensive matrix computations, a high-end GTX CPU or a Tesla stream processor may buy you much more for the same price.

Also, if the choice is between cache size and architecture, a new architecture may bring more. E.g. my Core i7 MacBook royally beats some of our Xeon machines with 25MB cache, by virtue of having AVX with 256 bit wide registers for SIMD.

Of course, if you can have it all, take it all :).

They support ECC ram, which is pretty important for some people. I believe the pre-fetchers are more aggressive on the Xeons as well, to make more use of the available memory bandwidth available with multiple QPI connections.