Benchmark Results: Bandwidth And Streaming
Here are the bottlenecks: the fastest integrated storage controller in terms of bandwidth is Intel’s ICH10R, which goes up to 688 MB/s in RAID 5 and 616 MB/s in RAID 0. However, LSI proves its MegaRAID SAS9260-8i as the superior product, delivering more than 1 GB/s on only six Intel X25-E SSDs.
However, our streaming tests delivered higher throughput than the bandwidth numbers would allow, so please take the interface benchmark with a grain of salt, since we don’t know the reason for this behavior.
At peak throughput, LSI’s controller wins again, reaching an outstanding 922 MB/s in RAID 0 and 761 MB/s in RAID 5. The others are all slower at peak throughput, but no solution falls below 520 MB/s (AMD 780a in RAID 5) except when running in degraded mode.
Oops! Write performance is a significant issue on the AMD and Nvidia systems in RAID 5 and in degraded mode. RAID 5 write throughput is down to 77 MB/s on Nvidia’s 780a SLI MCP and to 186 MB/s on the AMD SB750. Intel can maintain 440 MB/s, and you need a professional RAID card such as LSI’s to deliver fast 511 MB/s, even for RAID 5 writes.
This performance issue grows worse when a drive fails. In the case of a degraded array, all solutions drop to performance numbers that are much slower than an indiviudual, single 7,200 RPM drive would otherwise be. AMD and Intel write at extremely poor speeds: 29 and 28 MB/s, respectively. Nvidia at least maintaints its regular RAID 5 performance at 78 MB/s. That’s not fast, but at least it’s something.
LSI scores again thanks to its 512 MB DDR2-800 cache memory, which buffers lots of data even when the array is crippled.
