Intel Quad-Core Memory Performance

[Michael]

One of the many benefits of Fully Buffered Dual Inline Memory Modules is the ability to have up to six memory channels per memory controller. Each memory channel can also support up to eight memory modules. With that said the total number of possible modules is 48 (permitting the motherboard can handle that much), but how do the numbers of memory channels in use affect the performance of Intel's new quad-core Clovertown processor? With last month's introduction of the Intel Xeon 5300 Clovertown series we have decided to look again at Intel's FB-DIMM memory performance. In this article we not only look at the pure memory bandwidth but we also see how it correlates to real world gains as we time the compilation of the Linux 2.6.19 kernel as well as running rounds of Enemy Territory and Quake 4.

Article: http://www.phoronix.com/vr.php?view=8206

[fphillips]

8 x 512MB FBD-533 on 4 channels:
PHORONIX copy: 2014.77
PHORONIX Scale: 2016.36
PHORONIX Add: 1985.11

For comparison, here is results from my dual 5160 (3GHz)
4x2GB FBD-667 using 4 channels on 5000X:

ramspeed 2.4.1 UP compiled for i686:
INTEGER BatchRun Copy: 2414.22 Mb/s
INTEGER BatchRun Scale: 2334.57 Mb/s
INTEGER BatchRun Add: 2122.86 Mb/s

Here are results using 2 and 4 cores, respectively:

ramsmp 3.3.1 SMP compiled for i686 -p2:
INTEGER BatchRun Copy: 3990.67 Mb/s
INTEGER BatchRun Scale: 3884.67 Mb/s
INTEGER BatchRun Add: 3661.25 Mb/s

ramsmp 3.3.1 SMP compiled for i686 -p4:
INTEGER BatchRun Copy: 3985.57 Mb/s
INTEGER BatchRun Scale: 3942.61 Mb/s
INTEGER BatchRun Add: 3503.89 Mb/s

The tech docs for my S5000XVN say "Peak theoretical memory data bandwidth is 6.4GB/s with DDR2-533 and 8.0GB/s with DDR2-667."
It would be interesting to see if the quad cores can get any closer to that.
Also, notice how 2 cores nearly doubled the throughput, but 4 cores didn't do anything. So, I would say your results are cpu-limited and you aren't giving an accurate picture of maximum performance.

[Michael]

A reader submitted the story to Digg: http://digg.com/hardware/Intel_Quad_...ry_Performance

[1c3d0g]

Awesome performance. If I was still into desktops/workstations I'd definitely grab one of those monsters...