Huge Truthiness in IBM marketing

Wednesday May 23, 2007

Honestly I'd much rather blog about good news, talking about good products, good performance techniques and interesting new ways to look at how datacenters are evolving. But, when people look at the IBM announcements and the huge amounts of "truthiness" I just must point these things out.

OK let's look at this one:

IBM states: "processor bandwidth of the Power6 chip - 300 gigabytes per second - could download the entire iTunes catalog in about 60 seconds"

The system must be fast, hey wait a minute that wasn't system bandwidth it was processor chip bandwidth. Was it peak or measured? Peak doesn't mean anything. What does it deliver as system-wide measured bandwidth? Could it really download (which means move it from here to there)?

This would all have been easy if IBM just published the easy-to-run STREAM benchmark, which IBM ran on all of the POWER5+ systems. (http://www.cs.virginia.edu/stream).

I'm also surprised that there were no 3.5GHz and 4.2GHz results published. Also given the range is the 4.7GHz a hot-house flower? It'll be interesting to see what they really ship in June 8.

IBM's marketing now seems to run on "Truthiness" so that means we'll have to keep showing the facts to keep things straight. I need to go off and wash my face now.

Sun's Delivered Memory Bandwidth Leadership: Stream Benchmark

Wednesday Apr 18, 2007

Sun has faster delivered memory bandwidth than the best that IBM or HP can do. The Sun SPARC Enterprise M9000 beat IBM p5 595 by 10% on Stream TRIAD benchmark. The Sun SPARC Enterprise M9000 beat the HP Integrity Superdome by 33% on Stream TRIAD benchmark. The Sun SPARC Enterprise M9000, running with 2.4GHz SPARC64 VI processors, delivered a Stream TRIAD benchmark result of 227.1GB/s.

Don't let the core count confuse you, IBM cores cost over twice Sun's cores. Look at the other benchmark results posted to see that IBM costs more, is slower, and has fewer cores - but it is the best IBM that offers.

Be careful to compare measured/delivered bandwidth, other vendors sometimes try to confuse with peaks.

Stream Performance Chart - GB/s (1 MB=10^9 B, *not* 2^x B, bigger is better)

System	GHz	cores	COPY	SCALE	ADD	TRIAD
Sun SE M9000	2.4	128	224.4	223.1	224.2	227.1
IBM p5 595	2.3	64	186.1	179.6	200.4	206.2
HP Integrity SuperDome	1.6	128	154.5	153.0	169.5	170.8
HP Integrity SuperDome	1.6	64	116.1	114.6	127.9	128.7
Sun SE M9000	2.4	64	114.9	114.6	130.0	134.4
IBM p5-575	2.2	8	77.9	81.2	96.7	100.5
Sun SE M8000	2.4	32	60.3	60.2	69.3	69.6
Sun SE M5000	2.15	16	24.8	24.8	25.2	25.3
Sun SE M4000	2.15	8	12.6	12.5	12.7	12.7

Benchmark Description

The STREAM benchmark is a simple synthetic benchmark program that measures sustainable memory bandwidth (in MB/s) for simple vector kernels. All memory accesses are sequential, so a picture of how fast regular data can be moved through the system is portrayed. Properly run, the benchmark displays the characteristics of the memory system of the machine and not the advantages of running from the systems memory caches.

STREAM counts how many bytes that were read plus how many bytes that were written. For the simple "Copy" kernel, this is exactly twice the number obtained from the "bcopy" convention. STREAM does this because three of the four kernels do arithmetic, so it makes sense to count both the data read into the CPU and the data written back from the CPU. The "Copy" kernel does no arithmetic, but for consistency, counts bytes the same way as the other three.

The sequential nature of the memory references is the benchmark's biggest weakness. The benchmark does not expose limitations in a system's interconnect to move data from anywhere in the system to anywhere.

Disclosure Statement:

Stream is a publically available benchmark and can be found at http://www.cs.virginia.edu/stream. Results as of 4/13/07.

System Configuration

Systems under test:

• Sun SPARC Enterprise M9000
• 64 x 2.4GHz SPARC64 VI processors
• 1TB memory
• Solaris 10
• Sun Studio 12