Server Clash: DELL's Quad Opteron DELL R815 vs HP's DL380 G7 and SGI's Altix UV10by Johan De Gelas on September 9, 2010 7:30 AM EST
Putting It All Together
Finally, we have been able to offer you a comparison of real OEM servers. In this article, we tried some new approaches with our testing methods: we measured and compared response times and energy consumption, instead of the usual focus on "throughput" and "maximum/idle power". It is important to take a step back and look at all our benchmark data from the point of view of a server buyer.
Let's start with the quad Xeon 7500 server: the SGI Altix UV 10 or QSSC-4R. Based on our performance numbers alone, we felt that one quad Xeon 7500 server could replace two or more dual Xeon servers as the performance/price was right. The price is about 2.5x higher than a dual Xeon, but you get twice the performance, more expandibility (PCIe and DIMM slots), and superior RAS as bonus. Remember, a Xeon MP with a price/performance ratio that could rival that of a dual Xeon was a first.
But the appearance of the Dell R815 and the high energy consumption make the SGI / QSSC server retreat to its typical target (and very profitable) markets: ERP, databases with large memory footprints where RAS is not a bonus but the top priority. The performance was a pleasant surprise and the power consumption of CPUs was decent. Make sure you populate at least 32 DIMMs, as bandwidth takes a dive at lower DIMM counts.
The power consumption of the platform, especially looking at the idle numbers, remains a weak spot. We know that scalability and availability come with a price, but three times higher energy consumption than a dual socket server is too much to convince us that the quad Xeon platform is an attractive virtualization building block.
The HP Proliant DL380 G7 surprised with better than expected energy consumption and some really clever engineering (CPU cage, cold redundancy, energy management...). The high single threaded performance of the Xeon X5670 leads to low response times in many real world circumstances. At high loads, it is outperformed by the Dell R815 that is hardly more expensive.
With 80% higher DIMM counts and 80% to 85% higher throughput, the Dell PowerEdge R815 surpasses the rival HP DL380 G7 by a large margin, while at the same time costing only 20-30% more and needing just as much rack space. That is amazing value. While the price/performance ratio blew us away, we were also hoping that a single R815 could beat the performance/watt ratio of two HP DL380 G7s by a significant margin. That would have been the cherry on the cake, but it did not happen.
The server is not too blame; rather, the CPUs consume more than the ACP ratings that AMD mentions everywhere. The truth is that the CPUs at high load consume much closer to their TDP numbers than ACP ones. However, the performance per watt ratio of the complete server is still competitive. The lower single-thread performance per core is a disadvantage in applications with complex webpages. We would avoid the low end Opteron 6100s.
The bottom line is that Dell's R815 can replace two HP DL380 G7s at a much lower investment cost, with about the same energy costs and lower management costs. Having to manage half as much physical servers should after all also lower the operation costs. Dell's PowerEdge R815 materializes AMD's promise of the "Value 4P server".
My special thanks goes out to Tijl Deneut for his benchmarking assistance.