A4000 - motherboard FAST RAM simms

[CLS2086]

Hi,

I want to know what could be the interest to put FAST RAM on the A4k mobo, and a good reason for not putting simms there.

Also, can i replace the chipram simm by a faster one (i don´t care about the size as i know only 2mb could be used) to get any SPEED benefits or will it fails like an Atari STe with more than 2Mb with games ?

My A4kD is running well my an MK1-060 plus 112 mb which work in a kind of autoconfig mode !

I plain to put in it a DCE external FF, a CV64/3D, VlabMotion, Ariadne II, Prelude ZII, 1 big ide hdd and also 1 scsi, 1 yamaha cdrw and wonder if the PSU will last long...

[alexh]

http://aminet.net/package/util/boot/SpeedRamsey

[Tension]

Does that really make any difference.  I always thought it didnt increase performance if the access time was quicker...

Can a techie explain??

[alexh]

Tension wrote:
Does that really make any difference.

Yes. Not a lot but it does. There are many other tweaks that do much more though.

Tension wrote:
I always thought it didnt increase performance if the access time was quicker...

Eh? By having a shorter DRAM cycle time, you can get more cycles in a fixed time period?

Tension wrote:
Can a techie explain??

How in depth shall we go?

The speed rating on a DRAM (RAS) is roughly half a DRAM's minimum cycle time. In the A3000 or A4000, the standard DRAM cycle time is 200ns.  The most recent RAMSEY device (DRAM controller) has a "skip" mode that cuts the standard cycle down to 160ns.  This works with 60ns DRAM and perhaps some 70ns DRAM, and cuts out one "wait state" from all DRAM cycles.

The effects of this speed increase are somewhat reduced when using accelerators which support burst access. (NOTE: A3640 doesnt support burst access)