AMD's Barcelona: benchmarks

03 Oct 2007 09:14

AMD's long-awaited quad-core server CPUs finally arrived last month, with clock speeds up to 2GHz. So how do they perform? We have some preliminary results.

On 10 September 2007, AMD launched its first quad-core Opteron server processors. Codenamed Barcelona, these chips are initially destined for 2-way and 4-way servers that will hit the market in November. Later, we'll see quad-core processors for desktop systems too — the first PCs powered by the AMD Phenom are due in December.

Opteron models from the 2300 series are designed for 2-way systems, while 4-way servers will be built around the 8300 series. Meanwhile, Intel has had quad-core server processors available since November 2006, in the shape of the Xeon 5300 series. And just before AMD's Barcelona launch, Intel introduced a new 4-way server platform, codenamed Caneland, based on the Xeon 7300 'Tigerton' chips and 7300 'Clarksboro' chipset.

Both of the new quad-core Opteron series use 4 x 512KB of Level 2 cache and a large 2MB Level 3 cache. The clock frequencies of the new chips are disappointing at first sight, AMD's current production processes only allowing speeds up to 2GHz. However, the manufacturer hopes to be able to offer quad-core Opterons with higher clock speeds (up to 3GHz) soon. But even with their relatively low clock speeds, AMD's first quad-core server processors deliver convincing performance levels, as the benchmark results presented in the next section show.

Opteron (Barcelona) processors for 2-way servers

Model	2350	2347	2347HE	2346HE	2344HE
Clock speed	2GHz	1.9GHz	1.9GHz	1.8GHz	1.7GHz
Level 2 cache	4 x 512KB	4 x 512KB	4 x 512KB	4 x 512KB	4 x 512KB
Level 3 cache	2MB	2MB	2MB	2MB	2MB
Power consumption (TDP)	95W	95W	68W	68W	68W
Price (in 1,000-unit quantities)	$389	$316	$377	$255	$209

Opteron (Barcelona) processors for 4-way servers

Model	8350	8347	8347HE	8346HE
Clock speed	2GHz	1.9GHz	1.9GHz	1.8GHz
Level 2 cache	4 x 512KB	4 x 512KB	4 x 512KB	4 x 512KB
Level 3 cache	2MB	2MB	2MB	2MB
Power consumption (TDP)	95W	95W	68W	68W
Price (in 1,000-unit quantities)	$1019	$786	$873	$698

Performance

Performance
No AMD-sanctioned Barcelona systems were available for testing before the 10 September launch, although a few Tyan machines with beta BIOSes, early versions of the processors and prototype motherboards were circulating.

As a result, the benchmark results for the new quad-core Opterons reported here are from tests undertaken by AMD and IBM. The performance data for Intel's Xeon processors are taken from various manufacturers' figures reported on the SPEC benchmark site.

Benchmarks for integer (SPECint) and floating-point (SPECfp) operations show that AMD's new quad-core Opteron trails the Intel Xeons when running single-threaded applications (SPECint2006). Only if several applications are running at the same time (SPECint_rate2006) can the quad-core Opteron keep up with Intel's chips.

The Xeon's single-thread advantage is mainly due to the Intel Core microarchitecture's more effective command processing. Intel's Core processors can implement four instructions per clock, to the Opteron's three. When it comes to running multiple threads, the Opteron's more effective inter-processor connections over HyperTransport and the integrated memory controller allows it to regain parity.

This is why the 1.9GHz Opteron 2347 matches the 2.0GHz Xeon E5335 under the SPECint_rate2006 benchmark. The AMD advantage is greatest when multiple floating-point computations are processed (SPECfp_rate2006). Under this test, the 1.9GHz Opteron 2347 beats the Xeon E5365 clocked at 3GHz.

2-way server performance

Model	AMD Opteron 2347	Intel Xeon E5335	Intel Xeon E5345	Intel Xeon E5355	Intel Xeon E5365
Frequency	1.9GHz	2GHz	2.33GHz	2.66GHz	3GHz
SPECint2006	11.3	15.5	16.9	18.6	20.8
SPECint_rate2006	83.2	82.8	89.6	96.0	103
SPECfp2006	11.2	n/a	15.2	16.6	n/a
SPECfp_rate2006	73.0	56.8	60.8	63.3	66.9
Price (in 1,000-unit qualitites)	$316	$316	$455	$744	$1172

Conclusion

Conclusion
With only a few benchmark results available, it's not possible to reach any definitive conclusions. Even so, it's clear that the quad-core Opteron has a distinct advantage when handling multi-threaded floating-point operations. It's worth noting that the SPEC benchmarks can only serve as a guide since they represent the maximum performance level when running code that's optimised for the appropriate CPU architecture. However, many real-world applications are not optimised in this way, and so it's not possible to generalise the SPEC suite results.

Further testing will give a clearer picture of the performance differences between AMD's and Intel's quad-core processors. As far as virtualisation is concerned, though, AMD's Rapid Virtualization Indexing offers a clear advantage over Intel's frontside-bus-based architecture. For many IT managers, this could be reason enough to prefer AMD's quad-core processors over Intel's chips. However, the virtualisation software must support this extension: VMWare will support Rapid Virtualization Indexing in ESX Server 3.5, which is due to ship in December.

When it comes to desktop applications, AMD's current maximum clock speed of 2GHz for its quad-core chips is not sufficient to keep pace with Intel's Core microarchitecture. Single-threaded applications, such as 3D games, abound on the desktop, and here the Intel processors offer a clear performance advantage. As a result, AMD is only likely to ship desktop quad-core chips in December if the production process permits higher clock frequencies.

Benchmarks

Benchmarks from AMD's quad-core Opteron launch

Source: AMD

Story URL: http://reviews.zdnet.co.uk/hardware/components/0,1000001694,39289773,00.htm