Installing an AM3 CPU into an AM2 board

[CGBS]

Hello, I am wondering if anyone here has ever put in an am3 or even an am2+ cpu in an am2 board. I have the Gigabyte m61p-s3, which is AM2, but the CPU compatibility list does include the Phenom II X4 925 (AM3, 95w)..

The only thing I am really concerned about is this note:

If you install AMD AM2+ CPU on AM2 motherbord, the system bus speed will downgrade from HT3.0(5200MHz) to HT1.0(2000 MT/s) spec; however, the frequency of AM2+ CPU will not be impacted.

Do you think this will make a significant difference? For reference, I currently have an X2 4000+ (2.1ghz, slightly overclocked). It's an aging processor, and I'm thinking even with the HT going to 1.0, it will still be a fairly large upgrade for me, but again, I'm not sure.

Here's the CPU support list for my board: http://www.gigabyte.com.tw/Support/Motherboard/CPUSupport_Model.aspx?ProductID=2434&ver=#anchor_os

[shiny_red_cobra]

I think you will notice a big performance improvement, but since you have nothing faster to compare it to, then you won't even know if you're not getting the full performance from your CPU, you'll just be happy that it's faster. I say go for it and see what happens. It won't be slower than before, that's for sure!

[Draconian Guppy]

I remember not long ago, before I went intel line, some reviews stated that they didn't see that much of a performance hit unless using really demanding applications like several copies of a video encoder running + gaming at the same time. Don't take my word for it though :) I found it googling months ago for the exact same thing "AM3 on Am2 motherboard".

off topic and thread stealing LFS? Woot shiny_red_cobra

[Vice]

The benefits of the AM3 CPU outweigh the cons of running it in an AM2 board. As Draconian Guppy says the HT3.0 vs HT1.0 thing is not really that important.

And just to give you an idea of the bandwidth here:

AMD's HT1.0 = 6.4 GB/s (0.8GHz to 1.0GHz)

Intels FSB = 12.8 GB/ps (1.6GHz)

Intels QPI = 19.2 GB/ps (2.4GHz) - (This is used on all the i7's except the Extreme editions)

AMD HT3.0 = 20.8 GB/s (2.6GHz)

Intels QPI = 25.6 GB/ps (3.2GHz) - (This is the Extreme Edition chips and Xeons)

AMD HT3.1 = 25.6 GB/s (3.2GHz)

You will only really find yourself in trouble if you use a quad core AM3 and max all cores to 100% in a very memory intensive task. And when I say trouble I really only mean deminished performance compared to an AM3 chip in a HT3.0/3.1 capable system.

btw just incase anyone is more interested in the HT specifications and speeds. AMD only use 16-bit wide interconnects on their HT implementation but the spec itself is quite capable of 32-bit implementations which takes the HT3.0 speed from 20.8GB/ps to 41.6 GB/s and the HT3.1 speed to 51.2 GB/s which is just under double Intels QPI. But of course as I just said AMD don't use the 32-bit implementation (yet).