Results: Server Profile Testing
Workload Profiles
For as long as programs to exercise I/O activity have existed, professionals have sought to emulate specific workloads with them. We put our SSD DC S3700s through their paces with a handful of tasks based on basic enterprise-style I/O patterns
| Workload Profiles | ||
|---|---|---|
| Web Server | 100% Read / 0% Write | 0.5 KB 22%, 1 KB 15%, 2 KB 8%, 4 KB 23%, 8 KB 15%, 16 KB 2%, 32 KB 6%, 64 KB 7%, 128 KB 1%, 512 KB 1% |
| Database | 67% Read / 33% Write | 100% 8 KB |
| MS Exchange Server Emulation | 62% Read /38% Write | 100% 32 KB |
| File Server | 80% Read /20% Write | 0.5 KB 10%, 1 KB 5%, 2 KB 5%, 4 KB 60%, 8 KB 2%, 16 KB 4%, 32 KB 4%, 64 KB 10% |
Web Server Workload Profile
The Web server profile is fairly complex, consisting of eight different transfer sizes. Though dominated by .5 KB, 4 KB, and 8 KB transfers, there are several other sizes in the mix too. This profile involves 100% reads, but our SSD DC S3700-based arrays are almost equally strong when it comes to random writes.
Scaling appears identical to what we saw previously as drives are added. Again, performance doubles from the four- to eight-drive arrays, while the 24x configuration is a bit over 100% compared to the 8x setup. We could serve quite a few webpages with two dozen SSD DC S3700s.
Database Workload Profile
The database workload is super simple. It's just an 8 KB transfer size split between 67% reads and 33% writes.
The 24x array just touches the 500,000 IOPS mark. That's hardly surprising, since we should see almost exactly half of the I/O every second with two times the 4 KB transfer size. Since both the 4 KB read and write tests yield close to 1 million IOPS, 500,000 IOPS in the database profile is expected. Bandwidth is just IOPS multiplied by transfer size, so it stays essentially the same in all of these tests.
MS Exchange Workload Profile
Most traditional Iometer-style email server workloads are perfectly adequate. Just to mix things up, we're emulating MS Exchange mailbox activity with 32 KB blocks split between 62% reads and 38% writes.
These are really the first results we can't adequately explain. Run after run, we're touching 200,000 IOPS with our 24x array. That wouldn't be so strange, except 200,000 IOPS is a monumental 6.25 GB/s. The 3 TB array consisting of four SSD DC S3700s maintains 40,000 IOPS, regardless of queue depth. At over 1,200 MB/s of throughput, those are totally consistent results. We double that with eight drives and quadruple it with twenty-four. Perhaps we've found the perfect storm of settings? Since the outcome seems too good to be true, take these results with a grain of salt.
File Server Workload Profile
The file server profile is almost as complex as the Web server profile, except 20% of the transactions are writes and the majority of accesses are 4 KB. It's not a terrible representation of an average consumer/client workload, either.
On average, each I/O is worth approximately 11 KB of throughput.
The scaling is absolutely smooth and beautiful as more SSD DC S3700s are added to the mix. From 50,000 IOPS with the four-disk array up to 325,000 with the 24x arrangement, performance increases linearly with both drive count and workload intensity.