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ECS KN1 SLI Extreme Motherboard
Overclocking
Overclocking on the KN1 SLI Extreme is a little strange to me. If you are going for the complete overclock, and by that I mean 1:1 Memory:Base Clock frequency, then it's quite easy. You simply adjust the "CPU Frequency' and all clocks are raised at the same time. However, you can only do that if your RAM is capable of going over the typical PC3200 speed of 200MHz (yah yah, 400MHz DDR, but in the BIOS it's 200MHz). If you are dealing with value memory then overclocking becomes a bit trickier in that you cannot set the memory speed absolutely, its always relative to the CPU frequency and you have do some math. What complicates things is the lack of a clearly spelled out divider setting in the BIOS. According to the manual, Memory Speed Index (from now on I'll call it the Index) controls the memory speed when set to manual configuration. But, if you set it to 200 and raise the CPU frequency, the memory frequency is raised also. I confirmed this with CPUZ and the display on the Corsair XPERT Memory. For example, if you set CPU frequency to 216, your memory will run at 216MHz also even though the Index says 200. In reality, this setting acts as the memory divider. It's setup to work with standard RAM speeds of DDR200-DDR400 and doesn't expose any other memory dividers. This really isn't ideal as you want to run your memory as close to its rated speed as possible for best performance. To do that you would need more control over the memory divider and there simply isn't any. This could severely impact performance on your overclocked system as, in my example, the 8% gain in CPU speed would be offset by a 15% drop in memory performance. It is possible that you could obtain a 200MHz memory clock with a 166 Index, but it would require your CPU frequency to be set to 254MHz which is rather high for most CPUs. The moral of this story is, for the most effective overclocking on this board, you need to have memory that will run at as high a base clock speed as you intend to run your CPU. For more information on the memory divider in AMD systems, follow this link. Another strange thing about the KN1 SLI Extreme's overclocking is the CPU voltage control. However, unlike the strange memory divider, this is actually pretty handy. Rather than stating the voltage explicitly, which requires you to know the stock voltage and raise accordingly, you specify additional voltage in 25mV steps. So you can choose +25mV, +50mV, +75mV etc! This made adjusting the CPU voltage a little bit easier on me. Well now that I have the oddities of the KN1 SLI Extreme overclocking explained in far more detail than anyone probably wanted, it's time to go over the overclock that I was able to achieve. Using the Corsair Xpert Memory, which is essentially XL memory with a fancy display, I have the ability to run at 500MHz with 3-3-3-8 timings and stock voltage. This allows me to use the 1:1 memory divider to obtain best performance. To test system stability during the overclocking testing I ran Prime95 on torture test mode. I didn't have the time to run it overnight but each setup was required to endure two hours of this test before I considered it stable. I started raising the CPU frequency in 10MHz steps. At 230, I had to raise the CPU voltage +25mV to achieve stable operation. I jumped to 240 and the system would boot but would not run Prime95 more than a few minutes without failure. I tried upping the voltage an additional 25mV for a total of +50mV, but had the same problem. I backed off to a CPU frequency of 236 and I was able to run for nearly an hour before Prime95 reported an error. Finally I dropped down to 234 and was able to run Prime95 error free for my allotted time. This number is in line with the overclocking results I have seen on some other sites so it really didn't surprise me any. For my 3500+ processor, this meant I went from 2200MHz to 2574MHz, an increase in speed of 17% which ain't too shabby. I reran the Doom3 and Half-Life2 benchmarks and you can see the results of this increase in speed.  
Half-Life 2 @ 1024 x 768 (With Sound)
(Show All Graphs)
93
85
0
FPS
120
93
85
0
FPS
120
91
83
0
FPS
120
Half-Life 2 @ 1600 x 1200 (With Sound)
(Show All Graphs)
90
82
0
FPS
120
80
75
0
FPS
120
71
69
0
FPS
120
Doom 3 @ 1024 x 768
(Show All Graphs)
135
129
0
FPS
150
108
107
0
FPS
150
73
73
0
FPS
150
Doom 3 @ 1600 x 1200
(Show All Graphs)
71
71
0
FPS
100
55
55
0
FPS
100
39
39
0
FPS
100
The performance impact of our overclocking is best seen with the Half Life 2 benchmark. At all resolutions and AA/AF settings, there is a jump in performance, though it is much less as the graphical settings get cranked up. With Doom3, only the lowest of settings gave a noticeable performance gain. The reason you see little improvement in performance in Half-Life 2 with settings cranked and in all the Doom3 tests is that the system is more GPU-limited than CPU-limited in those instances.
Page 1: Introduction
Page 2: Board Layout Page 3: Bundles and Extras Page 4: Software (and fun with Tech Support) Page 5: Test Setup and Synthetic Benchmarks Page 6: Real-World Benchmarks Page 7: Overclocking Page 8: Conclusion 
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