GeForce 040 - sloooow SCSI? :(

[mechy]

Perhaps it's the SCSI to CF reader and CF card?  I had this exact accelerator back in the day with a 4GB SCSI-II HD and it screamed.  Was getting like 6MB/s.

Interesting trick considering the gvp gforce 040 uses the Am33c93a (same as WD -08/am33c93a in the A3000) which specs in the data sheet at 5MB/s max in synchronous mode,and that's in laboratory setting most likely. so if you even see 4MB/s you would probably being doing well.



the pcd series card reader are not as fast as the mfg specs for the same reason,most likely lab specs. I have attained 3.9 MB/s from it with a class 10 SDHC 4GB card from transcend on the csppc scsi. I doubt anyone will see this on the same speed on narrow scsi cards. Of course the benchmarks are hard to trust.

[mechy]

I'm not sure how I would change that?

My jumpers are set based on the information I found here:

http://www.bigbookofamigahardware.com/bboah/product.aspx?id=179

and on the amiga.resource.cx site.  All caches are enabled and burst mode is on.  Motherboard is a 6.4 with full ECS, MegaChip, Indivision, and heat sinks everywhere.  As far as I can tell everything works great on both the boards except my clock chip, LOL (still struggling to get that working).

gvpscsictrl is the utility you need to set synchronous mode. it should be on the gvp install disk i think

Also another note, if you are using any external devices,i seem to recall the gvp does not supply term power.


I wonder if you can do speedgeeks 33c93a scsi chip overclock hack for more speed? feel like being a guinea pig on the gforce mike?

[mechy]

There is a good chance the 33C93A is already running at 14MHz this being a later model/revision accelerator card.

The 33C93A is rated for 16 MHz and therefore is NOT overclocked at 14 MHz... but it does need to be configured correctly (for reliable synch mode operation) at any supported CLK speed.

Ok, good to know. I should of checked first before speaking-you didn't overclock it, just brought it close to its rated speed.
 i have no idea what the Gforce runs it at.
There is a 20mhz version of the chip also, it may be plcc style only(edit- no there is a DIP version). Have you tried these?
I wonder if there would be any gains on overclocking it,assuming it would tolerate it?

[mechy]

Well obviously my memory is lapsing a little then.  It was 4-5MB/s.  This was around 1997, so forgive me.  All I know is the machine was very fast and the HD was much faster than a A2091.

No worries, we are all getting old. I wish i could remember everything i knew

[mechy]

So after poking around with gvpscsictrl and HDToolbox for a while, it turns out the only way I was able to format one of my spare CF cards into Synchronous mode was with the much maligned HDInstTools.  Neither of the other applications had an option for it (gvpscsictrl is really just for slow old drives and removable storage, SyQuest drives, etc.).

After formatting and prepping the card SysSpeed reported that it was faster, but SysInfo said it was exactly the same speed.  Really I don't have much faith in either application, or in HDInstTools for that matter, LOL.    What tools are kids these days using to measure their Amiga HD speeds?

Turning on synchronous has nothing to do with format partitioning-it doesn't have any ill effects on a already formatted or installed hd. gvp tools allowed you to turn on any device as synchronous(many controllers make it all or nothing). gvscsictrl was the tool if i recall.
HdinstTools messes with the rdb in a non standard way.

latest ver of the gvpscsictrl is here:  http://www.gvp-m.com/updatejapan.html

beware if you try to use normal rdb standard tools on the hdinsttools prepped drive,i think it may corrupt it.

Btw, are you using sfs or pfs? you will never get good speed on FFS.

[mechy]

Mike,
   i just downloaded the gvpscsictrl from the link above, if you look in the tooltypes of the prog it shows SYNCHRONOUS ON/OFF/TOGGLE in there.
i *thought* it had a menu selections to toggle it on off for each device on the chain,but maybe my mem is failing me. the tooltype suggests it is there tho.

Btw, at the end of the day i suspect the guru rom will be the only help for it,which is hard to find. Ralph will not give out the board design to make new guru roms,he claims that there are still stores selling it,but there are none.. probably software hut listing it still makes him think that.
Gvp had a long history of bad scsi roms and i avoided most their stuff except for the A530(which had the same rom/scsi troubles). the 2091 is no peach tho

It is amazing gvp could cripple scsi on a accelerator capable of 32bit to where their own zorro2 card was slightly faster.

The best thing would be a blizzard 2040/2060  or DKB wildfire,then you can have near 10MB/s...