Radeon/Mediator as FastMem (HowTo)

[Ratte]

This guide is for ZIII-Amigas (A3000/4000) only !!!

http://www.a1k.org/forum/showthread.php?goto=newpost&t=17108 (org. german-guide)

Even before I bought a Mediator for my A4k (Mediator4000Di) I thought about the idea to add some of the gfxmemory from a radeon to the amiga memorypool.
Last night I had some time to try it out.
(If there is allready a guide or tool out there ... i didnt found it.)

My current setup is a A4k (Blizzard4030/50Mhz) with 2 mb chipmem & 16MB fastmem (onboard) and a Mediator4000Di with a 64MB Radeon 9250.

How to ...
First open/create the file "sys: prefs/env-archive/mediator/radeonmem" and replace/insert the comment "15 MB" direct at the begining of the file.
Save the setting and reboot to activate it.

Now your radeon as "only" 16MB graphicsmem (doublesize of a cvppc).
1 MB is reserved for PCI-communication ( thats the reason why we used "15 MB" ).
All other memory is unused (64MB Radeon = 48MB unused / 256MB Radeon= 240MB unused)

Next step:
Start the tool "CheckBoards" from the Picasso96-archiv (its inside of the "debug"-directory).
CheckBoards should find a gfx-board named Radeon with ? 3dfx Chipset (driver-bug) ? and a memorysize of 15712256 bytes if you dont made any mistakes.
If you own more than one pci-card, keep the "MemoryBase" of the gfxboard in mind!

With the Mediator-Software you received a tool named "pciinfo" in your c:-directory.
If you call "pciinfo" you´ll get a full list of all installed pci-cards including the used memoryareas.
Compare your "MemoryBase" from CheckBoards with the MemoryAreas from pciinfo.
If you found the correct pci-card keep also the end of its memoryarea in mind.
My 64MB Radeon is (for example) at $5000.0000 - $53ff.ffff.
Our current setting is using only the first 16MB for gfx ... $5100.0000 - $53ff.ffff are unused and free!!!

Last step is to add the memory to the memorypool:
Download the "addmem" tool from aminet.
And add the following line to the end of your "user-startup" inside of the sys:s-directory:
addmem 51000000 to 53ffffff pri 10 name pci-memory
The memoryareas could be differ from my example, it depends on your setup.

A "avail flush" could be nice behind the addmem-command,but it is not really needed.
Reboot and ...
... Done.

Have fun with your cheap memexpansion.
(btw. os4-research cant be done, as long as iam waiting for my repaired csppc from a german reseller)

regards
Ratte / a1k.org

[Ratte]

Much slower, especially when reading. VMEM is not meat to be read.

Yes, you are right.
Today I found some time to make some tests.
I started "Analyser" and made MemTests for over an hour ... no errors.
On a1k.org we had an older discussion regarding a (new) ZIII-memoryexpansion and we had collected some benchmarkresults from different memorys and expansions.

The Radeon/Mediator-Combo seems to be comparable to the DBK3128.
The user ville9/a1k.org send us results from his DKB3128.
reading 7.7 mb/s & writing 4.6 mb/s
The Radeon/Mediator results are:
reading 5.1 mb/s & writing 7.7 mb/s
A FastlaneZIII is faster ...
reading 15.5 mb/s & writing 8.6 mb/s

In normal use it is not different to any other memory.
But it is not comparable to memory on cpu-cards!

On the other side, this memory is really cheap ...

[Ratte]

The delivered Radeon9250 64MB bundled with the Mediator (bought 1-2 month ago) is a normal 3,3V Radeon.
Elbox modified the Card with a powerconverter ...
... on the same way it can be done with a 256mb version from ebay.

btw. the radeon.card driver for p96 is for 9200 and 9250 radeons.

pictures from the bundled radeon-card with powerconverter
http://www.a1k.org/forum/showpost.php?p=264387&postcount=31
(click on the pictures for fullsize)

ragards
Ratte/a1k.org