[Beowulf] power usage, Intel 5160 vs. AMD 2216

[Mike Davis]

Donald,

I have spun up Sun x4100 dual core, dual processor to 100% processor 
usage and normal HD writes and measured the actually powerusage at 267 
watts. Obviously higher than normal HD usage (such as swapping) would 
drive the number up, but I was very pleased with these results as well 
as those of the x2200 machines.


These tests were made with CentOS 4 installed.


Mike Davis



Donald Becker wrote:
> On Tue, 10 Jul 2007, Jon Bernard wrote:
> 
> 
>>Vendor A estimates that at peak load a compute node with two AMD 2216s,
>>4 GB of 667 DDR2 RAM, a hard drive, and an IB board will draw 265 watts.
>>Vendor B estimates that such a node will draw 450 watts.
> 
> 
> Considering that the regular 2216 is 95W peak (the 'HE' version is about 
> 65W), and the memory and IB card are both pretty warm, 265 watts is 
> unrealistic.  Multiply a realistic max power by a power supply 
> efficiency and you'll get about 450 watts.
> 
> There is way to get that lower number: 2216HE processors, and very efficient 
> (93% would be exceptional, high 80s more realistic) power supplies.  But 
> that will be significantly more expensive.  Easily enough $$ that you would 
> know if that's what you are buying.  (We use 'HE' processors, special 
> memory and highly-efficient power supplies in our blade systems to make 
> the thermals work, and system price/MIPS looks pretty bad compared to 
> standard 1U products.)
> 
> The chipsets and base processors are same between vendors, and the IB 
> cards and disks are about the same.  The memory power use will vary a bit, 
> but you might get different numbers between the sample and shipped nodes.  
> The biggest variation will be the power supply efficiency.  And even there 
> it will be vary significantly with the power draw.
> 
> We've measured between 50% and 93% efficiency.  The worst are the supplies 
> in old generic 1U cases, which hopefully we won't see again. There is 
> a significant cost difference between today's low-end, low-efficiency 
> supplies and the better 80+% units.  Doing an extra conversion e.g. to 
> 50VDC then to the final board voltage, won't improve the 
> overall numbers, but will move the conversion and thermals to "behind the 
> curtain".
> 
> We could get into an interesting discussion about the best way to decrease 
> the typical power use of a cluster.  The best way to do this is with 
> software -- laptop-style power control, and powering nodes down.  But when 
> purchasing and installing clusters you have to design for that 
> long-running job that stays at the peak power draw and thermal state of 
> the cluster.
> 
>