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Diagram to go here about how the whole thing goes together
At the budget levels of this project I am comparing this purchase with the ability to purchase a 200Mhz Pentium Pro (albeit with only 256Kb internal cache). Unfortunately this particular chip does not include MMX instructions - which, as there is little software available which currently uses it, is not strictly necessary. I would however like some future proofing.
During the life of this machine this chip will definitely be upgraded - probably in about 3 years time, and (given the use of the AGP bus) so will the motherboard. Given these two constraints the choice should be based around the most cost effective solution today (the next few months).
It would seem that the choice is between the Pentium II or the AMD K6.
My current opinion (subject to price and availability) is that the AMD K6 operating at 200 or 233Mhz has the best choice between price and performance. I have decided to allow a budget of £350 which is approximately the price of a 200Mhz Pentium with MMX or a 200 Pentium Pro with only the smaller (256Kb) L2 cache. I have yet to find out what level of K6 this will allow me to buy as I have not found any UK outlet quoting a price.
Does this CPU need or come with a heat sink and or fan over and above that found in a normal case?
Within the budget constraints of this build, I would expect to be able to go build a system with up to 64Mb of main memory, although it is questionable whether my current use of the machine would justify this amount. My current machine uses 16Mb of memory, but is swapping to disk quite frequently. I therefore conclude that the minimum memory should be 48Mb, but the decision as whether to go for the full amount will depend on the view taken as to whether this memory will last the full life of the machine.
There are really only two choices for memory, EDO ram and SDRAM. As far as I can work out from http://www.sysdoc.pair.com/ there is considerable difference in clock cycles, with the former taking 5-2-2-2 (or 11 cycles) to read four bits out of each piece of memory, whilst the latter (on motherboards using the 430TX chipset) uses 5-1-1-1 (or 8 cycles). I am not sure if I have this correct, but does this not mean that the memory is effectively one and a half times as fast for the same speed of memory bus?
It also appears that the EDO ram will not be fast enough for Memory Bus speeds in excess of 66Mhz, whereas SDRAM can be employed up to 100Mhz (I haven't yet found any argument that convinces me of this). Given that this will still be appropriate for the bus of the future it seems worth the additional expense and a commitment of 64Mb. I have yet to see any prices quoted for a 64Mb DIMM (which would probably be the best), the budget is on the basis of 2 32Mb DIMMs.
In order to get the best speed, and support for SDRAM at full speed (5-1-1-1 clock cycles) the Intel 430TX chipset should be used on the motherboard. The following boards have appeared in a UK magazine review
Current suggested UK sources seem rather tentative on availability and price.
The choice is between Windows 95 and Windows NT. I am an experienced user with Windows 95 but have had little experience of Windows NT. From what I can see on newsgroups, many games will not work under Windows NT (does it support DirectX games though, and with what relative performance?), and particularly, DOS games will need a reboot (and a dedicated FAT16 partition if NTFS is to be used - FAT16 will be difficult with a 3Gb disk). Windows 95 could be configured with OSR2 and FAT32 to overcome the 2GB disk limits for FAT16.
Benchmarks for the Pentium Pro and K6 processors both show that Windows NT is faster than Windows 95 (I assume that that is because the switch to 16bit mode costs these pipelined processors more time than the extra software layer introduced by NT and its processing model, so would be the best choice if games could be got to work. My main concern here is that the availability of both standard drivers under NT for the peripheral devices that I propose and whether or not the 3D cards need different DirectX 3D drivers for NT. Can anyone provide me with answers to this?
I can only find prices for Windows 95 upgrade, but since I am replacing an old 386SX, I believe this is still a valid licence position.
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page last updated 9th November 1997
© 1997 Alan Chandler