Saturday, December 17, 2005

Why did AnandTech handicap the Opteron?

Jason Clark & Ross Whitehead at AnandTech has conducted a benchmark on the future INTEL Bensley platform with the Dempsey CPU and Blackford chipset. However, one eagle eye on AMD board spotted something unusual, Anand's engineers setup the machines with 8GB ram and then ran the tests under 32 bit Windows under PAE mode. The following was from their setup:
"Windows 2003 was configured with /3GB and /PAE switches in the boot.ini to support the 8GB of memory used for our tests. SQL Server Enterprise was set to use AWE extensions, and a maximum memory limit was set at 6144MB."

This is werid. Both the Opteron and Dempsey are 64 bit chips. We know that runing Opteron under 32 bit in PAE mode is much slower than native 64 bit mode. We know the Opteron runs up to 170% faster under 64 bit mode. In most newer benchmarks published by HP and others, Windows Server x64 and 64 bit SQL server were used. PAE mode is for suckers, Linus said PAE is basically like DOS extender and is slow. AMD only added PAE mode as a compatibility measure.

And the test AnandTech ran was some kind of custom script, only two tests. Why didn't they run some standards tests? Such as the Apache bench, the MySQL bench, and the Unix bench Anandtech had been using?

Even with both hands tied to the back, the Opteron 280 tied with the future Dempsey while consuming about half the power.

I hope this Anandtech article was not paid by INTEL and I would like to see some realistic tests. Having 4 Opteron 280 cores and 8GB ram running 32 bit is like running Pentium IV in DOS only mode.

AnandTech had a benchmark testing AMD64 and INTEL EM64T under both 32 and 64 bit mode. The conclusion was INTEL runs slower under 64 bit than 32 bit mode, while AMD64 is faster in 64 bit mode. If this is still the case with Dempsey, then Anandtech may run each chip in its best light: INTEL in 32 bit and AMD in 64 bit.


Blogger Sharikou, Ph. D said...

AnandTech sent a response. Their main points:
1)Both Dempsey and Opteron were " tested in a 32-bit environment, which doesn't favor one over the other."

2) "very large part of the Windows IT world is not yet running 64bit Windows"

My comments:
1) AnandTech's own benchmark showed that Opteron is substantially faster under 64 bit mode than 32 bit mode, while the Xeon is faster in 32 bit mode than 64 bit mode. Therefore, AnandTech was running Opteron in slow mode and Xeon in fast mode in the test. Also, PAE was kludge but INTEL had been doing it forn a long time, AMD only added it as a compatibility measure.

2) AnandTech has mostly used Linux in the benchmarks in the past. Also, the fact most IT are using 32 bit Xeon is irrelevant. Dempsey and Opteron are both intended for 64 bit computing.

6:03 PM, December 18, 2005  
Blogger Sharikou, Ph. D said...

Some sharp guy on Yahoo message board pointed out that since there is zero adoption of Dempsey in the global Windows IT world, AnandTech should forget about the Dempsey all together....

6:54 PM, December 18, 2005  

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