English Amiga Board


Go Back   English Amiga Board > Support > support.Hardware

 
 
Thread Tools
Old 17 December 2009, 05:15   #1
desantii
Registered User
 
Join Date: Oct 2009
Location: Oswego, IL
Posts: 125
Speed of SCSI controller

Just curious I have a a SCSI to IDE converter and use a GVP combo board in my A2000, the speed reported in sysinfo is 2,100,000 bytes/sec but if I use no accelerator and GVO HDD controller I get 2,300,000 as the speed. Does it make sense that an unaccelerated HDD controler get higher speed thatn the controller of an 030 50mhz? If so is there nay benefit of raunning SCSI of teh acclerator vs the ZII HHD controller?

Just as refrence, the same setup in an A3000 030/25 gives 2,900,000 as speed
__________________
Amiga 2000, 030 50mhz 9mb ram
Amiga 3000, 030 25mhz, 18mb ram
desantii is offline  
Old 17 December 2009, 11:28   #2
ancalimon
Supernormal

ancalimon's Avatar
 
Join Date: Jul 2007
Location: Istanbul / Turkey
Age: 38
Posts: 1,229
I think it's because the SCSI uses very little CPU?
ancalimon is offline  
Old 17 December 2009, 20:51   #3
rkauer
I hate potatos and shirts
rkauer's Avatar
 
Join Date: Oct 2007
Location: Sao Leopoldo / Brazil
Age: 53
Posts: 3,482
Send a message via MSN to rkauer Send a message via Yahoo to rkauer
Pending on what accelerator you have in your A2000 (GVP? Other?), a GVP SCSI Zorro-II controller is faster and gives you a bit more memory (4 to 8Mb, depending on what more you have installed).
rkauer is offline  
Old 18 December 2009, 01:19   #4
desantii
Registered User
 
Join Date: Oct 2009
Location: Oswego, IL
Posts: 125
I have a GVP 030 50mhz with 8mb, the HDD controller card is also a GVP with 8mb

thanks
desantii is offline  
Old 18 December 2009, 12:08   #5
whiteb
Fanatically Amiga.

whiteb's Avatar
 
Join Date: Apr 2002
Location: Melbourne, Victoria, Australia
Age: 50
Posts: 1,548
Well I had to struggle to understand what you were asking, but where an Accelerator card gets its speed from, is Onboard Ram, as well as Onboard HDD controllers.

The less data that has to be shifted, in competition with the Custom chips for clock cycles the better. This is where the Cyberstorm cards come in to play and truley FLY (or any CPU card with HDD, RAM and CPU on the one unit), is they have the CPU, Ram and HDD all on the one card (Or Daughter cards), the only slowness that is needed, is to transfer data out of the "Sandbox" so to speak.

Quote:
If so is there nay benefit of raunning SCSI of teh acclerator vs the ZII HHD controller?
Absolutely........, The moment that you have to "Halt" the card to wait for Zorro (or System) time to export data to another device, there goes any advantage you have speed wise. That is why any DECENT card, will have CPU, RAM and HDD all in the one unit, to minimize any wait periods.

The card can focus on what it is doing, fetching data off its own HDD, to its own ram, for its own CPU's execution. The only wait states it needs to do, is sending data to and from the Custom chips.

Example....., the A530 for the A500. Had its own HDD, Own Ram, Own CPU. The only time it had to call the rest of the system was to give or take from the Custom chips.
whiteb is offline  
Old 18 December 2009, 12:17   #6
whiteb
Fanatically Amiga.

whiteb's Avatar
 
Join Date: Apr 2002
Location: Melbourne, Victoria, Australia
Age: 50
Posts: 1,548
Quote:
Originally Posted by desantii View Post
I have a GVP 030 50mhz with 8mb, the HDD controller card is also a GVP with 8mb

thanks
Yes, But the 030 50Mhz with 8MB, and the HDD with 8MB of ram are separate cards yes ?

Then the cards must each compete, with the rest of the system to send data back and forward to each other. You incur penalty wait times (Red Traffic lights). An ALL IN ONE card (CPU, RAM, HDD) all on the one card keep getting more Green lights.

Imagine the ENTIRE system is a City. CPU HDD and RAM are all on the same 6 lane 200MPH highway... 6 lanes in EACH direction.. but the Custom chips all sit on a 60MPH, single track side road (Zorro).

Now, If your HDD was on the single lane road, you must wait for permission to travel down the road, because other traffic (Graphics, Sound, etc) use the same road. Does it not make sense to make your HDD to use the same 6 lane EACH direction road instead of the single lane ?

That is the problem..., Zorro shares the same BUS (Road) as Any other system resource. You need to move the HDD over to your own private High Speed highway to cut out the red lights.
whiteb is offline  
Old 19 December 2009, 04:18   #7
rkauer
I hate potatos and shirts
rkauer's Avatar
 
Join Date: Oct 2007
Location: Sao Leopoldo / Brazil
Age: 53
Posts: 3,482
Send a message via MSN to rkauer Send a message via Yahoo to rkauer
Some old GVP units have SCSI transfers slower than the specialized GVP HC+8. And if the accelerator is the ancient A3001 (030 @50MHz + IDE controller), better stick with the separate controller.

Also the extra memory will not hurt, albeit slower than the directly available at the accelerator.
rkauer is offline  
Old 19 December 2009, 11:43   #8
alexh
Thalion Webshrine
alexh's Avatar
 
Join Date: Jan 2004
Location: Oxford
Posts: 12,232
Going way off topic.

Most 030 cards which are limited to 8Mbytes usually keep their RAM in Zorro II address space. HC8+ keeps its memory in Zorro II address space. This space is limited to a maximum of 8Mbytes. Meaning you cannot operate a fully populated 030 accelerator at the same time as a fully populated HC8+.

I am very surprised you were able to get these two cards to work at all! You must be lucky and have an accelerator which uses the upper address range for RAM.

Which brings up another point. It means the accelerator RAM is not "DMA'able" meaning when the 030 is enabled SCSI accesses are either CPU initiated not DMA or there is an extra overhead of memory copies?
alexh is offline  
Old 19 December 2009, 12:47   #9
Loedown
Precious & fragile things

 
Join Date: Feb 2009
Location: Victoria, Australia
Posts: 1,945
Quote:
Originally Posted by alexh View Post
Going way off topic.

Most 030 cards which are limited to 8Mbytes usually keep their RAM in Zorro II address space. HC8+ keeps its memory in Zorro II address space. This space is limited to a maximum of 8Mbytes. Meaning you cannot operate a fully populated 030 accelerator at the same time as a fully populated HC8+.

I am very surprised you were able to get these two cards to work at all! You must be lucky and have an accelerator which uses the upper address range for RAM.

Which brings up another point. It means the accelerator RAM is not "DMA'able" meaning when the 030 is enabled SCSI accesses are either CPU initiated not DMA or there is an extra overhead of memory copies?
In a previous thread, I was discussing why my A2000 with GVP 030 combo and HC+8 were a bit slower than expected, they do both work, quite happily even.

Paul
Loedown is offline  
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
AztecMonster on SCSI controller Tryphon support.Hardware 3 31 December 2013 01:54
Blizzard 1230 Mk IV and SCSI controller merlin3d support.Hardware 6 01 March 2008 16:43
SCSI controller for A1000? davidpc support.Hardware 6 29 August 2007 21:15
Apollo 2030 SCSI Controller Drake008@ support.Hardware 5 10 April 2007 01:19
Name for the Blizzard2040's SCSI controller driver LUKas007 support.Hardware 2 24 June 2002 15:26

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 06:29.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Page generated in 0.07123 seconds with 15 queries