So, how does Rackspace compare to AWS, GCE, and Azure, at least as far as these fairly simplistic benchmarks go?
• Rackspace’s cheapest instance type, the 512MB Standard, beats out Amazon pretty handily for price-per-performance, but is more expensive both Microsoft Azure’s Extra Small and Google Compute Engine’s f1-micro, from my experience. That said, Rackspace appears to guarantee the performance of the 512MB more than either GCE or Azure, so if you’re mostly interested in the low end, Rackspace may win out over time for you here.
• With HVM virtualization, Rackspace’s 1GB Performance will likely turn in better UnixBench scores than anything that any other major IaaS provider sells for the same price or less.
• With HVM virtualization, Rackspace’s Performance family will likely turn in UnixBench scores that are competitive with AWS and GCE at roughly the same price points, although there are also notable differences between the providers. At roughly less than $1,500/month/server on-demand, Rackspace offers significantly less RAM than either AWS or GCE (Rackspace only offers # of cores = GB of RAM until you hit 15GB RAM); however, Rackspace touts its SSDs and network bandwidth as superior.
• On the issue of I/O, it's interesting that AWS and GCE have focused on IOPS available to specific instances, whereas Rackspace seems to focus on the adjacent metrics of network bandwidth (both external and internal). The most-touted IOPS number that I found on Rackspace’s site is “Disk I/O up to ~35,000 4K random read IOPS and ~35,000 4K random write IOPS,” which comes with the caveat that this is “shared across the host” -- in other words, subject to noisy neighbors. This really requires further investigation with I/O benchmarking, but I think Rackspace would be in a better situation if it could offer guaranteed IOPS for specific instance/storage connections.
My overall impression of Rackspace is of a successful managed hosting company that has been trying to react to AWS for several years now, without significant success. Rackspace may have the best managed hosting and private/public/hybrid cloud consulting/hosting services, but HP, Datapipe, Dimension Data, SoftLayer, and CenturyLink -- among others -- look like solid competitors in this space.
Moreover, while those kind of services might have been what organizations wanted five years ago, I think AWS has made the industry re-examine exactly how we should think about infrastructure. In particular, services that provide developers with exceptional APIs and self-signup seem to be doing better than services that have focused on consulting and outstanding live support.
I think Rackspace is doing what it needs to do right now: get server options online that provide performance (both CPU and I/O) competitive with the top IaaS vendors. For the company's sake, I hope it can speed up its development/release cycles and that there remains a significant market that wants to pay Rackspace to manage above the infrastructure layer.