Hi,

Is there any real noticable difference between 1000MHz on a MOBO ro 2000MHz?

thanks

There are no Front Side Buses (FSB) of these frequencies.

The closest are the Intel Core 2 at 266 MHz (1066 MHz effective), or most Xeon 5-series at 333 MHz (1333 MHz effective). There are similar matches in HyperTransport buses on AMD systems which can be found at 800 MHz (1600 MHz effective) and 1000 MHz (2000 MHz effective). AMD does not rely on the FSB in the same way an Intel processor does because Athlon 64s have memory controllers built into the processor itself. This reduces the traffic between processor and chipset.

Intel bus and AMD HT cannot be compared directly. The speed of the interface is not defined by the frequency, but by how many bit can be transferred per clock:

For the Intel GTK+ Bus, it transfers 64 bits, four times per clock. Transfering data four times per clock is called Quadruple Data Rate (QDR), or sometimes Quad-Pumped, and is why the 266 MHz FSB is marketed as 1066 MHz. To calculate the bandwidth, the calculation is (Frequency in MHz * 64-bits per clock * 4 pumps per clock) / 8 bits per byte = Megabytes per second. You can make it easier by doing a lot of the math before hand: 64 * 4 / 8 = 32, so:

266 MHz * 32 = 8.5 GB/s
333 MHz * 32 = 10.7 GB/s

The HyperTransport interconnect is a serial link that transfers 32 bits, twice per clock. Transferring data twice per clock is called Double Data Rate (DDR), or sometimes Double-Pumped, which is why a 1000 MHz HT link is marketed as 2000 MHz. The bandwidth calculation would be (Frequency in MHz * 32-bits * 2 pumps per clock) / 8 = Megabytes per second. 32 * 2 / 8 = 8, so:

800 MHz * 8 = 6.4 GB/s
1000 MHz * 8 = 8 GB/s

When we rank the common speeds (in descending order), you can see how little MHz means anyway.

1600 MHz HT = 6.4 GB/s
800 MHz FSB = 6.4 GB/s
2000 MHz HT = 8 GB/s
1066 MHz FSB = 8.5 GB/s
1333 MHz FSB = 10.7 GB/s

How much it really impacts performance depends on a lot of factors. It depends on which interface type you're talking about, how fast the CPU is, what sort of application the system is being used for, what speed the RAM is, what type of graphics card is installed.

If you want an answer to your question, you're going to have to give at least some indication of what you're trying to ask.

well , it was jus that when i was choosing a motherboard socket 939 sli ready, some of them under the specifications window, and under FSB speed, some motherbards were 1000 and some were 2000. I was jus wondering wether it really mattered which one i got. :-\

It is both a misconception and an error then.

Firstly, the HT speed is not the front side bus. Secondly, there is no 1000 MHz HT. All but a few socket 939 solutions have a 2 GHz HT link. The exceptions are some VIA chipsets and the nForce 4 4X, which have 1600 MHz; all SLI solutions at 2 GHz.

I would be cautious when purchasing from anyone who makes both of these mistakes.