First post, by megatron-uk
My cache chips finally arrived today so this is the first test I've done with them installed.
My board (revision 1.2 running the last BIOS release 0306) originally came with 4x512kbit chips installed. I've now replaced these with 4x1024kbit chips instead. They are still at the same rating of 15ns and I have not changed the tag ram chip which is listed at the same size for both 256kbyte and 512kbyte configuration.
First of all, with J15/16/17 jumpered for 512kb the board does in fact power on and POST without any problems.
My memory and cache timings are all set at the most aggressive, except the memory speed, which is set to 'Faster' and not 'Fastest' (I'm using two 70ns 32mb fpm simms at the moment - I don't have any 60ns modules available), and both cpu and motherboard cache are set to write-back. All burst-mode PCI/Memory/CPU settings are enabled.
So, the tests I've performed so far:
Booting my standard config.sys which uses himemx.exe.....
.... a failure here. I'll need to investigate this.
Using a clean win98se boot floopy and himem.sys.....
.... no issues. I've since swapped my config.sys to use himem.sys instead of himem.exe, so booting from HDD is now ok.
Checking CPU is still identified ok.....
... Yep, all ok.
Some Sysspeed output:
Test that the cache is actually working....
.... looks good to me!
I know I can get some better main memory speed results with some 60ns modules, but I'm just glad that the cache is actually working. I wasn't sure it would as it doesn't seem anyone else has one of these boards configured for 512kb (even though it's a standard configuration listed in the manual).
Speed wise, the cachechk results for block sizes up to 512kb are are virtually the same as those were for blocks up to 256kbyte for my 256kbyte configuration (not surprising, as the chip speed ratings and bios settings are identical to before). The memory block transfer timings are now the same all the way to 64mb now that the full 512kbytes of cache is installed, this dropped above 32mb (IIRC) with the smaller amount of cache that was installed previously.
It will take more 'real world' use to see if it speeds things up any, my guess is probably no more than a couple of percentage points, if that.
My collection database and technical wiki:
https://www.target-earth.net