X-bit labs

Workstation Processors Duel: AMD Opteron against Intel Xeon (page 15)

Category: CPU

by Ilya Gavrichenkov

[ 12/21/2005 | 08:44 PM ]

Quake 4

Besides PCMark05, we decided to add one more “game” test (in the direct and indirect meaning of this word). Namely, we decided to test the performance of our workstation platforms in a gaming application, such as one of the latest and more popular games – Quake 4. There were several reasons why we included this test into the list of our approved benchmarks. The thing is that the graphics card manufacturers have finally implemented SMP support in their drivers. And as we have found out during our previous dual-core CPU test session, some OpenGL games really get a performance boost if run on systems capable of processing several parallel computational threads simultaneously. Quake 4 is exactly a game like that.

However, we shouldn’t expect professional workstations to show any terrific results in Quake 4. As we see, systems with dual-core processors yield to those with single-core CPUs because of the lower clock frequency of the former. At this point the graphics drivers are optimized only for systems with two logical CPUs, so the potential of more powerful platforms is not fully utilized by the graphics drivers during parallel calculations.

In fact we could stop our Quake 4 performance discussion right here, if it hadn’t been for one fact. Last week id Software released patch version 1.0.5 for their shooter, where they promised to offer SMP support. In fact, there is nothing surprising about the appearance of this patch. All engines from this game developer have supported SMP for a long time now. However, since there was no real need for this support, it has never been finalized and was simply disabled just in case. Now, they have finally polished it off. So, let’s take a look at the results obtained in Quake 4:

The situation is pretty interesting. We can see how obviously changes the fps rate. However, it was not always the increase. In fact, the performance got faster only in those systems where we had four logical CPUs. For instance in the system built with Xeon 3.6GHz processors the results increased by 27.7%, and in the system with AMD Opteron 275 CPUs – by 25.5%. Note that the platform built with two single-core Opteron 254 CPUs got 5% slower, so that it yielded to the system with dual-core processors in it. As for the system with dual-core Xeon CPUs, the patched Quake 4 refused to run there at all. Looks like the eight logical processors were far beyond its understanding. So, we can say that Quake 4 with patch version 1.0.5 is first of all optimized for systems with four logical CPUs. Dual-processor workstations are not the only type of platforms that might have four logical CPUs. They may also be found in desktop systems built with Pentium Extreme Edition processors.