First post, by jasa1063
- Rank
- Oldbie
I put together an Intel Marl system a few years ago. Official CPU support is up to a Pentium MMX Overdrive 200. I was just thrilled to get a Pentium MMX 233 working by just overvolting it, but in the back of my mind was taking it up to 400MHz with a K6-2 or K6-3 CPU. To do this I was going to need an interposer and an updated BIOS. I had already upgraded the BIOS to MR BIOS so that just left the right interposer to use. I was able to pick up an Evergreen Spectra 400 with a K6-2 400MHz CPU. I had one problem in the custom heatsink and fan were missing to clip on to the CPU socket because of the extra height and space taken up by the interposer board. SEKISUI #5760 thermal tape to the rescue as this eliminated the need for the retaining metal bracket on the heatsink. I installed everything and the system posted with the BIOS recognizing the CPU as an AMD K5. I used K6INIT to setup Write Allocate, Write Ordering and Write Combining. I then used CPUSPEED to enable the L1 cache as well as Data Prefetch. This works well for DOS. I used CTU for initialization of these parameters in Windows 98SE. I was really please with the results, but I thought I could do one better. The interposer from Evergreen supports voltages of 2.0, 2.2 & 2.4 as well as CPU multiplier up to 6.0. I decided to try a K6-III+. I set the voltage 2.0 and installed the K6-III+. The BIOS still recognized the CPU as an AMD K5. I just had to add the 6.0 multiplier K6INIT and enabled the L2 cache with CPUSPEED. I also updated these parameters in CTU for Windows 98SE.
All has been working well and the speed difference is just amazing. The one interesting thing is that base memory speed is less with the K6-X CPUs than the Pentium MMX. I am not going to post extensive benchmarks, but here are the results from Speedsys for the Pentium MMX 233, K6-2 400 & K6-III+ 400.
