Lab test: Sun’s octo-core SPARC is made to multitask
Sun SPARC Enterprise T5120, sporting eight cores with eight threads each, shines at virtualization and heavily threaded applicationsFollow @pvenezia
My T5120 evaluation unit came with the single, eight-core T2 CPU, 64GB of RAM, four copper gigabit Ethernet ports, two USB 2.0 ports, three PCI-E slots (two doubling as 10G Ethernet slots), serial and Ethernet service processor connections, and redundant power supplies.
Up front, T5120 well equipped for local storage, as it’s available with as many as four 2.5-inch 10K RPM SAS drives. I’m not entirely sure why Sun opted for the high concentration of local disk, as the nominal position of the T5120 is as a compute server, not a storage server, but given that they had the room, it’s not unwelcome. When used with ZFS, Sun’s revolutionary new file system, the internal storage options grow, especially in virtualization scenarios. It’s easy to see the T5120 supplanting many physical SPARC-based servers by collapsing their workloads into Solaris Containers that feed from the T5120’s 64-thread trough.
The other side of the T5120 is the low power consumption. The CPU runs at less than 95W, and the server itself runs relatively cool, hence the Sun CoolThreads designation. Certainly, in comparison to the behemoth Suns of yore, the T5120 steps lightly with both power consumption and heat generation.
A fix for ILOM
The management of the T5120 resides largely in the Sun ILOM (Integrated Lights-Out Manager), which is accessible via a serial and Ethernet connection. As with most of Sun’s SPARC-based servers, there is no frame buffer in the server, so the only management options are the serial console, SSH, or Web-based management tools. It seems to me that these tools have actually gotten worse over the past few years, as I’ve found it harder to work with later iterations of the ILOM than those of just a few years ago. As a case in point, the ILOM for the T5120 was slow, even when only using SSH, and relatively Byzantine to work with on both the Web and SSH interfaces. The Web interface looks and feels like the management interface found on nearly all Sun servers, SPARC-based or otherwise, with the exception that there’s no console applet. SSH to the ILOM is the only way to access the console remotely.
After consulting with Sun regarding the sluggish interface, I received a much newer firmware revision for the ILOM. Following that upgrade, the performance of the ILOM was significantly better on both the SSH and Web interfaces. As of this writing, the T5120s that are shipping now have this newer version installed. By the numbers, my evaluation of the management capabilities was running at a solid 7 until the firmware revision arrived, inching that score into low 8 territory.
Given the effort and care granted to the rest of the server, these issues are rather puzzling, but thankfully could be remedied with updated firmware, not updated hardware.
Naturally, the T5120 was built to run Solaris. In my tests, Solaris performed quite well on a number of standard tasks, such as Web and database work -- essentially any task that was sufficiently multi-threaded. As mentioned, the T5120 makes a great virtualization platform for these same reasons. But Solaris isn’t the only OS that can be run on the T5120. Ubuntu Server’s SPARC release runs as well. Although I did encounter some initial Ubuntu-related installation problems, after those were resolved, Ubuntu 7.10 ran cleanly. It was very interesting to run ‘top’ on that installation and see 64 CPUs appear, representing the fact that the UltraSPARC T2 offers each thread of each core as a separate CPU designation to the OS. Thus, eight cores times eight threads per core gets us to 64.
The overall performance of the T5120 under Ubuntu was roughly even with the performance under Solaris for normal tasks, though there are significant optimizations for the T2 processor in Solaris that will result in better FPU and crypto performance, at least for now.
Overall, the UltraSPARC T2 and the T5120 build upon the hallmarks of the first-generation UltraSPARC T1-based servers, and remind us that although the SPARC CPU may have been marginalized in recent years, it hasn’t surrendered, and may in fact be making a comeback.