SeaMicro Unveils 512 Atom-Based Server

1sockchuck writes "Stealthy startup SeaMicro has unveiled its new low-power server, which incorporates 512 Intel Atom CPUs, a load balancer and interconnection fabric into a 10u server. SeaMicro, which received a $9.3 million government grant from DOE to develop its technology, says its server uses less than 2 kilowatts of energy — suggesting that a single rack with four SeaMicro units and 2,048 CPUs could draw just 8 kilowatts of power. Check out the technical overview, plus additional coverage from Wired, GigaOm and VentureBeat."

Comments

What does a normal rack consume?

[Call Me Black Cloud]

I don't know if 8 kW is a lot or a little less than a normal rack would draw. The article doesn't say...how much power would a "normal" rack consume? Isn't there a measure of computing power vs power used?

Re:What does a normal rack consume?

[geekboybt]

That's not too hard to calculate. I usually budget 2 A for a dual-CPU 1u server. At 120 V, that's 240 W. 8 kW divided by 240 W = 33u of servers. Multiplied by 12 cores (allowing for the new X5600 series, ignoring hyperthreading on both Atom and Xeon), you get 396 total cores of standard Xeon in 8 kW. Meanwhile, they're advertising 2048 Atom cores in the same amount of power. So, the real question becomes how powerful ~5 Atom cores are compared to 1 Xeon core.

Low power, really?

[TheRaven64]

In all of the benchmarks that I've seen, clock for clock a Core 2 gets about twice the score of an Atom, sometimes more. The Core 2 uses a bit more than twice as much power, but if you have two Atoms you also need twice as many north-bridge chips and this pushes the power usage up to over what the Core 2 will consume. The newer Xeons do even better.

The first benchmark results I found that compared the two were PassMark benchmarks, where a 2GHz Atom scored 386 and a Intel Xeon X5680 at 3.33GHz scored 10620. The fastest Atom, the D510 at 1.66GHz, scored 662. Even if your code scales linearly, you need more than 16 of the fastest Atom that you can buy to replace one Xeon. Or, to put it another way, this 512-Atom machine is about as powerful as a 32-CPU Xeon.

A single Atom D520 draws around 13W, so 16 of them draw 208W. The Xeon will draw 130W. Drawing under 2KW for 512 Atoms means that they probably aren't using the fastest available ones. Actually, it means that they're drawing under 4W per Atom, which means that they're probably using Z-series Atoms, getting about half the performance of the D-series ones, so you'd only need about 16 Xeons for the same performance.

For most workloads, if the server is not busy, you'll get much better power usage from the Xeon as well. Power usage drops off dramatically when the CPU is not 100% busy. Unless you are turning individual atoms off completely, you can't scale back power usage nearly as well with the Atoms, as single processes that would not be CPU-bound on the Xeon will require an Atom core to run at full speed.

In other words, it sounds a lot more like greenwashing than anything that's actually sensible.

Re:Vitual center

[AigariusDebian]

Actually it is much more interesting to handle each of them as you would handle an individual virtual machine - so you have 512 nice low-powered virtual servers with each of them having a fixed and dedicated processor.

In fact such a load-out would be very useful for hosting companies - you can have a ton of small clients with minimal management or scheduling burden.

Re:What's the "bang for the buck"?

[robthebloke]

Almost, but not quite. The things that suck about the atom:

1. double precision. Use a double, and the Atom will grind to a halt.
2. division. Use rcp + mul instead.
3. sqrt. Same as division.
All of those produce unacceptable stalls, and annihilate your performance immediately. So don't use them!

Now, you'd imagine those are insurmountable, but you'd be wrong. If you use the Intel compiler, restrict yourself to float or int based SSE instuctions only, avoid the list of things that kill performance, and make extreme use of OpenMP, they really can start punching above their weight. Sure they'll never come close to an i7, but they aren't *that* bad if you tune your code carefully. Infact, the biggest problem I've found with my Atom330 system is not the CPU itself, but good old fashioned memory bandwidth. The memory bandwidth appears to be about half that of Core2 (which makes sense since it doesn't support dual channel memory), and for most people that will cripple the performance long before the CPU runs out of grunt.

The biggest problem with them right now is that they are so different architecturally from any other x86/x64 CPU that all apps need to be re-compiled with relevant compiler switches for them. Code optimised for a Core2 or i7 performs terribly on the atom.

Re:What's the "bang for the buck"?

[drinkypoo]

Then they screwed up, and they should have used ARMs, because a great deal of Atom's performance lies in its multimedia instruction set. Or in other words, if you're not pushing flops, you have a lot of hardware lying around unused. Atom delivers a lot of flops (or iops, for that matter) but doesn't shovel data any more efficiently than anyone else.