Tweaking and Overclocking
TWEAKING.Tweaking is area where this board shows its stars compared to the rest of the KX133 breeds of boards.
The Abit board includes SoftMenu III in its BIOS, anyone who's played with SoftMenu I or II before should easily be able to pick up the bits in the new III.
With the first official bios release RJ the Motherboard was extremely Stable, but did suffer from rather poor memory bandwidth which was even lower than the First AMD750 chipset motherboards which was suprising, considering the memory is now running at 133mhz.
Within a month of the KA7 release there have been a series of bios updates, firstly to sort out some compatabilities with some SCSI cards, Secondly and more important to us Tweakers they added a few entries in the Advanced Chipset Functions which enable the experienced user to seriously increase the memory performance on this board and wow they do make a difference!!!
Before I show you the results from this tweaking I must say that to enjoy the performance gains you must have a Decent stick of Sdram, We here used the Crucial 128mb PC133 CAS2, which has to be one of the best types of ram around. Some lesser makes of PC133 ram we found would not like to Tweak much above the default settings...
The bios is setup as default with ram set at HSTCLK which is 100mhz (or FSB), this needs to be changed to HSTCLK+PCICLK which is 133MHZ
In the Advanced Chipset Funtions screen,u will see the following settings.
Dram Bank Speed: 10ns, 8ns, Normal, Medium, Fast, Turbo
4-Way Interleave: Disabled, 2-way, 4way (Bios RY-)
Cas Latency: 2, 3
Firstly I ran SiSoft Sandra 2000 Memory benchmark, 3Dmark 2000 and Quake 3 Demo1 with the above settings at default.
3Dmark 2000 scored 5074 3dmarks
Q3 Demo1 averaged 97.9 Fps
Right then lets starting fiddling with a few settings
Firstly I enabled 4 way interleave to see what this would do,here is the answer.
Next I changed the Dram Bank timing from 10ns to 8ns then to Normal and ran the Memory benchmark again, but this did not show any improvements
When changed to Medium setting though we start to see more Improvements
4-Way Interleave Enabled
Cas Latency Set to 2
Dram Bank Timing set to TURBO
Right then with this Huge increase lets see what this does to the Quake3 and 3Dmark2000 scores
Quake 3 Demo 1 = Average 104.7 Fps A 6.9% increase over the default memory settings
3Dmark2000 = 5387 A 6.1% increase over the default memory settings
Well I was very impressed with this 6% performance gain just from Tweaking the Memory settings, I wonder what other gains are to be had via later bios updates,From my experience this board has the highest Memory Bandwidth when using SDRAM.
OverClocking.
The KA7 has full FSB tweaking via the system BIOS, along with core voltage adjustment. The advantage of this is that you dont need to crack open your Athlon 800 and stick a Golden Fingers device on our processor, you simply plug it in and play in the bios!
For this Operation I decided to UnderClock my Athlon 900mhz Cpu to 700 mhz (using a GFD) to See how this chipset can be Overclocked.
Right then, I decided to turn the Sdram Clock to 100mhz to make sure that the ram wasnt going to be the limiting factor.
After adjusting the FSB in 1mhz steps I reached a very respectable 130mhz Fsb (7x130=910mhz) knowing that this Athlon will do 950mhz Stable before the chipset fell over. So if you have an Athlon and want to overclock it quite seriously (as all Athlons love to be Clocked) this definately will allow you to nearly reach the limit of your core.
I decided then to try the RAM back at HSTCLK (FSB) + PCI CLOCK which means the ram was running at 163mhz, At first the Motherboard wouldnt boot, but As with most PC133 ram after you go above 140mhz you need to set the CAS delay back to 3 otherwise problems will occur. After changing the CAS to 3 the motherboard booted first time and ran stable at this setting, Showing that Our choice of Crucial Ram was a Good one .
Also there is the further option of being able to set the Cache Divider via the bios (RY revision) to 1/3, 1/2, 2/5 of CPU core speed, thus allowing Cpu's with slower cache chips to still be seriously overclocked without the cache being the limiting factor. We tested this option on our Athlon 750@900 with 1/3 (300mhz) cache divider and set it to 2/5 (360mhz) which worked according to WCPUID thus allowing a 20% increase in cache operating speed.
