Preview:Intel Harpertown Quad Core CPU

This month we got an opportunity to get our hands on the latest Intel's 45 nm

based Xeon processor codenamed Harpertown. We received a complete rack mountable

server with two 3.0 GHz quad core Harpertown processors, 16 GB RAM, and two 200

GB Sata hard-disk connected through a PCI-X RAID controller. We ran a set of

tests to see the performance of the server and got some really amazing results.

But before we talk about the tests, results, and performance of the server,

let's first understand what is this new processor 'Harpertown' all about.

What is Harpertown?



With the launch of the 45 nm Penryn processors, Intel has announced their

Penryn based Xeon (5400 series) models codenamed Harpertown, with higher front

end bus speed, 1600 MHz. This series of processors will be available from 2.6 to

3.2 GHz range. But the 2.6 GHz one will have a lesser bus speed which is 1333

MHz. Intel is even planning to launch a dual core version of the CPU with a

similar architecture which will be codenamed as Wolfdale and will be available

with frequency ranging from 1.89 to 3.4 GHz. In simple terms Harpertown is a

better, faster, and more energy efficient quad core processor if compared

against Clovertown (the current quadcore based Xeon CPUs). The key difference is

in the L2 cache, bus speed, and power consumption. For a detailed comparison

have a look at the table. Harpertown is supposed to replace Clovertown in the

near future.

Another highlight of Harpertown is its new instruction set. Harpertown comes

with Intel Streaming SIMD Extensions 4 (SSE4) instructions. This instruction is

today the largest unique instruction set addition since the original SSE

instruction set architecture was first used.

Setup and tests



To test the Harpertown in our test labs we ran benchmarks such as Linpack,

SunGard, and Netbench and our own developed BZip2 benchmark. We ran these tests

on multiple OSs such as CentOS 5 and Windows Longhorn Server RC0. The setup was

pretty much simple. We took the server as it is and only changed the RAM in some

cases. The only configuration made was a RAID 0 array of the two hard disks to

get the best possible read-write performance from the 5400 series server.

Test 1: Running Longhorn



We installed Longhorn on this server as this one would be the latest OS when

Harpertown would be released in the market. And most of us will be using

Harpertown Servers with Windows Longhorn pre-installed into it. So testing

compatibility and performance of Longhorn server was a must for us. While

installing Longhorn we really got surprised as the complete installation of

Longhorn took less than 10 minutes which generally takes around half an hour on

a core 2 duo extreme machine. We also gave a try to Longhorn's new hypervisor on

Harpertown and it worked marvelously with full virtualization support. We were

able to run seven dedicated guest systems on the hypervisor.

Test 2: Linpack



A server testing without Linpack doesn't make any sense. But this time

instead of running Linpack on a stripped down installation of OS with minimum

service running, we decided to run it on top of a full blown Longhorn

installation itself. We did this to see how much of actual performance a user

will be achieving while using Harpertown on a production environment with an OS

such as Longhorn.

Sungard risk analysis application took 203.12 seconds to complete the test job with the 8 core Harpertown server

With a bit of tweaking in the Linpack input file we were able to achieve

around 65 Giga Flops in no time. This result is till now the best performance

result we have got out of any server. The closest performer to this score was

the Connoisseur Skyrunner which was a dual Clovertown 3.2 GHz based server which

gave us around 53 Giga flops of floating point operations.

And as we ran Linpack on a full blown OS without stripping down any services,

we can easily say that after fine-tuning the OS we can easily achieve up to 70

to 80 Giga Flops sustained performance with Harpertown.

Bzip2



We also ran our self-developed Bzip2 benchmark which zips a huge number of

files simultaneously and stresses the processor and the hard-disk. The

performance which we got was not as good as we achieved in our Clovertown based

Connoisseur Skyrunner server. But the reason was apparent. The Bzip2 is a

benchmark which stresses both the processor and the hard-disk. The Harpertown

server, which we received, had just two disks whereas the Skyrunner had four in

a RAID 0 array which gave it an edge over this Harpertown server.

SunGard



SunGard is a financial risk analysis application which is also used for
stressing the processors. The application even lets you select the number of

cores which we want to strain. We ran this test on the Harpertown and ran it on

various cores to see the performance increase is linear or not when we increase

the cores. The result was not exactly linear. We saw a sudden drop between two

and four cores but the drop between six and eight was the least. For more

details see the SunGard graph.

The 'performance increase' with the increase in the number of cores was not linear

We also decided to see the per-core performance difference in a core 2 duo

extreme and Harpertown machine. To test this we took a Core 2 Extreme 3.0

machine with 2 GB of RAM and ran SunGard on it. So, essentially SunGard ran with

two processing threads. Then we took the Harpertown server and reduced its RAM

from 16 to 2 GB to make sure that the benchmark doesn't outperform just because

of the extra RAM it has. Then we ran SunGard on it too. We got around 15% of

performance benefit in the Harpertown 2 Core test which is a good result.

Bottomline: With the best performance among all the quad core CPUs, we have

reviewed, this processor is the choice of the future.

Harpertown gave 15% performance benefit in a machine running two active cores than a core 2 duo extreme machine