A month or so back I was fortunate to receive my first dual core CPU, AMD’s Athlon64 X2 4800+. I concluded that it was one of the best CPU’s ever made and it really hammered every other CPU on the market in the majority of situations/tests. With the X2 AMD took the route of making the product line sit in the high end price bracket with CPU’s ranging from £400-£750 ($550-$1000) depending on the model and so this high performance was to be expected. Today we are looking for the first time at Intel’s take on dual cores in the shape of the Pentium D 820. Interestingly this CPU is priced at £180 ($240) which puts it in the price brackets of single core CPU’s like the Athlon64 3500+ (Venice core) and should it outperform similar CPU’s it could well be a very tempting purchase. Let’s see how it compares

The CPU

The Pentium D 820 runs using the SmithField core at 2.8ghz and features two cores on a single die. Each of the is allocated 1mb of level 2 cache. Manufactured on the 90nm process the CPU features a 200mhz fsb and a multiplier of 14x.

Intel’s dual core design means that although the cores have their own cache they actually share the system bus, and therefore available bandwidth. The FSB in the case of the 820 is quad pumped to 800mhz differing from the 1066mhz of the newer P4 Extreme Editions. The slower FSB being shared between the two cores could well impact the memory bandwidth results and there may be situations where real world performance is impacted also. For example in tasks such as games which are single threaded the Pentium D 820 will act like a 2.8Ghz, 800fsb Pentium 4 without HT.

The new high-end dual core Pentium Extreme has support for hyper threading resulting in the ability to have a virtual 4 CPU’s running. This feature is not carried down the product line to the Pentium D range at this time so therefore you are limited to 2 real CPU’s.

One feature which is included though is 64bit support which makes the processor all the more competitive with the low-mid range Athlon64’s. Also included feature wise is SSE3 support (also recently added to new Athlon64’s).

Of course the CPU uses the now well established LGA775 connector and is cooled by any heat sink which works on Intel’s cooler design specifications.

Where as the X2 range from AMD works on pretty much any Socket 939 motherboard with a bios update choosing a motherboard for the Pentium D is slightly more complex. Both the 945 and 955 chipsets support Pentium D by default. The Nforce 4 also supports dual core CPU’s however its up to your manufacturer to enable support for each board (bios update), the same goes for Radeon Xpress based boards so unless your buying 945/955 check with your motherboard manufacturer before trying. (Note: Intel 915/925 chipsets do not support Pentium D).

Next: Test System