I'm helping my friend build a computer, and I know that pentium D's aren't that good, but he is on a budget, and it works with the motherboard hes getting so he might eventually upgrade to core 2 duo (gotta love run-on sentences!). Well anyways what si the difference between these two processors? this or that . They both have 800 mhz FSB, and 2.8Ghz, but one has 2x2mb L2 cache with 65nm, and the other has 2x1 with 90nm. On top of all this the one with 2x2mb L2 cache is a bit cheaper. So which one should he choose?

Hello,

I would go for the Intel Pentium D 915 Presler 2.8GHz 2 x 2MB L2 Cache LGA 775 Processor - Retail.

Reasons higher cache and smaller manufacturing process. looks quite versitile.

Yes, definitely the 915, overall better in all areas, including cost

Well, to answer your original question, the nm means the size of the memory chip (nano-meter?)
If you want to know more, search for the differences between high-density and low-density ram. As this is what these different sizes mean. I think the 2x2 is high-density. I don't think they would have any noticeable differences though. I would search google to see what size chip performs better or causes less heat.

Realize that I'm not really an expert on this though and am not sure if I'm totally right. Chip sizes and stuff like that can be pretty difficult.

Thanks everyone!

The manufacturing process (65nm or 90nm) doesn't have anything directly to do with the cache. It refers to the average size of structures on the chip. A processors with smaller part needs less energy to run and so produces less heat. This takes on an added importance with the NetBurst-into-flames architecture, which both processors you linked to refers to.

The 2x2MB and 2x1MB means that the first one has 2MB of cache per core while the second only has 1MB cache per core. Here, more is better.