Since 2000, I have had a system based around a Micro-Star MS-6163 BX Master mainboard. When I bought it, I also bought a MSI MS-6905 Master 1.1B slocket and a Celeron-II 533MHz which I had run at 840MHz since day one with no problems after increasing the voltage to 1.65V from the stock 1.5V. Two sticks of PC100 CL2 Micron RAM for a total of 256MB rounded out the system.
Lately, due to software becoming more bloated and inefficient, I was forced to contemplate an upgrade. CPU, memory, and video card were all considered. I decided to stay with the MSI BX board in the end, since it was still possible to obtain good performance from the platform, and I didn't want any external problems such as video card incompatibility, power supply issues, or problems fitting a new board into the Inwin A500 mid-tower case. I also wanted to keep the MSI board because its six PCI slots and single ISA slot are a perfect match for the expansion cards I am using. (Newer mainboards with ISA slots are very rare.)
Unfortunately, the Matrox G400 MAX appears to still be the best overall choice for 3D games, dualhead and TV-out performance, video playback, and open source drivers. (An option was to obtain an ATI 9200.) I ended up staying with the G400MAX. It has served me well.
Memory was a quick fix, with the caveat that I observe the compatibility constraints with BX boards and memory (http://homepage.hispeed.ch/rscheidegger/ram_bx_faq.html) and obtain memory modules with RAM chips organized as 16×8. The mainboard has four memory slots, for a potential total of 1GB memory (to install more than 3 memory modules, buffered memory is required). So, I obtained four 256MB buffered ECC 16×8 Viking sticks from Ebay for $60. The seller claimed they were CL2, but they turned out to be CL3. I obtained a $5 refund on that basis.
Now for the CPU issue.
Since this is a BX board, only 100MHz bus speeds are guaranteed to be stable with respect to the AGP slot (since the AGP bus only has 1/1 and 2/3 dividers). So a 133MHz CPU is a possibility, but I preferred to limit my search to 100MHz CPUs (also convenient since I had PC100 memory).
I also questioned the capability of the motherboard power electronics and my 300W Antec power supply to supply a hungrier CPU, but these concerns turned out to be irrelevant. Celeron Tualatin 1400/100/256KB SL6JV 33.2W / 1.50 volts = 22.1 amps
The motherboard BIOS could be an issue, because the CPU settings are done through software. In this case, the locked multiplier of Intel CPUs turns out to be beneficial, because we aren't dependent on the motherboard to set the CPU multiplier (only the bus speed). Some boards require an update to the embedded Intel microcode update: http://www.mrufer.ch/pc/tualatin4_e.html The slocket also has several adjustable settings for voltage and bus speed.
Several CPU choices were available, all Socket-370. (SECC-2 CPUs are hopelessly obsolete and expensive in comparison.) The board can physically take:
– Coppermine PIII which were made up to 1.1GHz at 100MHz and 133MHz bus speed on a 0.18 process and with 256K of L2 cache
– Tualatin PIII which were made up to 1.4GHz at 133MHz bus speed on a 0.13 process and with 256K or 512K (Pentium III-S) of L2 cache
– Celeron-II which were made up to 1.1GHz at 66MHz and 100MHz bus speed on a 0.18 process with 128K of L2 cache
– Tualatin Celeron (Tualeron) which was made up to 1.4GHz at 100MHz bus speed on a 0.13 process with 256K of L2 cache.
More information can be found here: http://processorfinder.intel.com/scripts/default.asp
We want the best combination of price, high clock speed, small process (for lower power consumption), and large cache. The 1.4GHz Pentium III-S is the best performing choice, but easily fetches $100 due to its rarity. It also runs on a 133MHz system bus and thus would have required more expensive PC133 memory. The second best choice is a 1.4GHz Tualeron, which runs on a 100MHz system bus. I obtained one of these for $30, which I consider to be a bargain.
The next challenge was interfacing the Tualatin to a Socket-370 Coppermine adapter in a motherboard designed to take slot CPUs. While the Tualeron will physically fit in a Socket-370, the electrical signals are different. I obtained what is referred to as a “Lin-Lin” adapter on eBay. This cost approximately $7, and is about a 5mm shim socket that sits in between the Tualeron CPU and a socket designed to take Coppermine CPUs.
So what I then had was a slocket, with the LinLin adapter installed, the 1.4GHz Tualeron CPU installed into that, and the Global Win HSF on top of it. When I reinstalled this, I was left with less than 1mm clearance between the top of the CPU fan and the second memory DIMM. I decided that the new Tualeron CPU, being built on a smaller process, did not need as massive of a heatsink as the old one did, and so I ordered a CoolJag 1U cooler from 1coolpc.com. This is a low profile cooler that is designed for use in a 1U-height rack mount. It works perfectly for giving a slocket more room too!
However, I was not so lucky when it came to correct functioning. Upon boot up, the system would freeze in the BIOS. After extensive troubleshooting, I found this page: http://overclockers.com/tips61/ which detailed an RMA program, long expired, for the MSI slocket I was using. Apparently, while the 533MHz Celeron I was using happened to be compatible with this slocket, MSI's opinion was that it was unusable with any Coppermine CPU, and by extension, my Tualeron+LinLin which appears to the system as a Coppermine CPU. New slockets cannot be found for sale anymore, and are incredibly rare even on the used market. I thought I was out of luck until a friend mentioned that he had a MS-6905 1.1 in storage. I traded him my 1.1B + Celeron (guaranteed to work with the 1.1B) for his 1.1, installed the Tualeron stack, and the system worked after that point.
If you are having problems getting the system to boot, clear the CMOS, and then set 400MHz (100×4) in the CPU soft menu. Also make sure both JP2 and JP3 are jumpered on the board (for automatic FSB selection).
In the end, I now have a 1.4GHz/256K/100MHz/1024MB/CL3/ECC system, which performs MUCH better with current software than the previous 840MHz/128K/105MHz/256MB/CL2 system. And there was no need to upgrade any other part of the system, such as motherboard, power supply, case, video card, etc. I have not yet done extensive 3D game testing, but I would imagine significant improvement in that area. Total cost of the upgrade was around $80, which is much less expensive than a system platform change would have been.
The only possible upgrade now, without changing the underlying platform to something more current, would be to use CL2 memory instead, but the CL2/CL3 distinction is a small performance hit.
The LunchBox discussion forum was very helpful in figuring out what to do about problems with this project: http://www.geocities.com/_lunchbox/