ASUS P5N32-E SLI Plus: NVIDIA's 650i goes Dual x16

Disk Controller Performance

The AnandTech iPeak test is designed to measure "pure" hard disk controller performance, and in this case, we keep the hard drive as consistent as possible while varying the hard drive controller. The idea is to measure the performance of each hard drive controller with the same hard drive.

We played back our raw files that are recorded I/O operations when running a real world benchmark - the entire Winstone 2004 suite. Intel's iPeak utility was then used to play back the trace file of all I/O operations that took place during a single run of Business Winstone 2004 and MCC Winstone 2004. The drive is formatted before each test run and a composite average of three tests on each controller interface is tabulated in order to ensure consistency in the benchmark.

iPeak gives a mean service time in milliseconds; in other words, the average time that each drive took to fulfill each I/O operation. In order to make the data more understandable, we report the scores as an average number of I/O operations per second so that higher scores translate into better performance. This number is meaningless as far as hard disk performance is concerned, as it is just the number of I/O operations completed in a second. However, the scores are useful for comparing "pure" performance of the storage controllers in this case.



The performance patterns hold steady across both Multimedia Content I/O and Business I/O with the SB600 outperforming the Intel ICH7R, Intel ICH8R, and NVIDIA 680i/650i chipsets in our non-Raid tests. The Promise controller on the DFI board is the slowest of all solutions with the Marvell controller on the Intel 975X performing only slightly better. The 680i and 650i MCP chipsets are different but their disk performance in our tests is basically alike. We also ran RAID 0 and RAID 5 tests on each controller with the results being in favor of the 680i MCP by around 2% over the 680i LT and 650i MCP in these particular benchmarks. Although our NVIDIA boards generally score lower in these "pure" throughput tests, we find their actual performance in disk intensive applications are generally equal to or better than the other solutions.

Power Consumption


Our power consumption numbers are based on our test setup for this article that consists of the MSI 8800GTX video card and our boards have C1E/EIST turned off. The 680i boards lead all in power consumption but the ASUS P5N32-E SLI Plus is right behind indicating that the 570 SLI MCP draws slightly more power than the 430 MCP on the true 650i boards. The P965 consumes the least amount of power at idle but around 10% more than the RD600 at load. The 975X still offers a decent level of power conservation compared to the other chipsets even though it is getting long in the tooth.

FSB Overclocking


While the ASUS P5N32-E SLI Plus offers very good overclocking capabilities, it quickly runs out of headroom near the 500FSB level. We believe this is a limitation of the 650i SPP based upon our results with other 650i boards. ASUS has extracted just about every ounce of performance out of this particular chipset. While it may not satisfy the extreme overclocker, the overclocking levels should be fine for a majority of users.

We found during overclocking that we had to set the CPU voltages a little higher than on the other boards to attain the same or better overclocks. We experienced this with the MSI 650i and EVGA 680i LT SLI boards, and it was generally due to tighter memory/chipset timings in order to improve the performance of the board at stock speeds. Overall, our overclocking experiences were very good provided we had the memory sub-timings dialed in for each memory type we utilized.