NVIDIA reference NFORCE 680i SLI motherboard straps dissected
Author: Grga Curkovic
Date: 20 May 2007

NVIDIA?s nForce 680i SLI became a very popular platform among enthusiasts, and mostly incarnated in form of NVIDIA?s reference design board. Part of the reason lies in the fact that this board is most affordable in price among 680i SLI boards, part in the fact that it is really good board. We use the same board as our reference board for all tests, and one might say we have a decent amount of experience with this board and a wide range of other components. While testing memories we noticed that the board sometimes behaves strange, and decided to find out what it?s all about.
We suspected that the strange behavior we have been experiencing had something to do with chipset straps. It is normal for any chipset to change straps when you increase the frequency, and the easiest way to measure those changes are memory tests. We decided to take the time needed and measure memory performance of our system at speeds from 1067MHz (stock speed) to our highest stable overclock, 1980MHz. During the tests the processor multiplier was set to 6, and memory timings were set to 4-4-4 2T. Those settings didn?t change at any point of the test.

We worked on our Black Pearl testbed assembled of the following components:
- EVGA NFORCE 680i SLI Black Pearl
- Intel Core2 Duo E6700
- OCZ PC6400 DDR2-800 CL3 Flex XLC
- OCZ GeForce 8800GTX
- OCZ PowerXStream 1000W
- WD Raptor 150GB

Our initial intention was to measure the performance in 3 MHz steps (12MHz in QDR rated FSB), and we started off at 1067 MHz. Check out our table on next couple of pages for results.