68000

All about ST/STE games

Moderators: simonsunnyboy, Mug UK, Doctor Bob Gordon, ICS, Moderator Team

alex
Retro freak
Retro freak
Posts: 10
Joined: Thu May 28, 2015 6:58 pm

68000

Postby alex » Thu May 28, 2015 7:18 pm

Hello neo geo 68000 12 MHz MIPS few have compared the atari?

User avatar
dlfrsilver
Atari God
Atari God
Posts: 1479
Joined: Mon Jan 31, 2005 1:41 am
Contact:

Re: 68000

Postby dlfrsilver » Sat May 30, 2015 12:48 pm

alex wrote:Hello neo geo 68000 12 MHz MIPS few have compared the atari?


What is the point of your question ?

The neogeo has a 68000, but it has nothing in common with the Atari ST or even STE.

The neogeo is a sprite/tile system helped by a powerful GPU. The ST is a framebuffer tied to a 68000.

Out of the processor, they have nothing in common.
Now SPS France representative since the 19th of June 2014. Proud to be an SPS member !

alex
Retro freak
Retro freak
Posts: 10
Joined: Thu May 28, 2015 6:58 pm

Re: 68000

Postby alex » Sat May 30, 2015 3:03 pm

Hello I mean if you can know how many MIPS correspond to 12 MHz?

User avatar
exxos
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 4933
Joined: Fri Mar 28, 2003 8:36 pm
Location: England
Contact:

Re: 68000

Postby exxos » Sat May 30, 2015 4:27 pm

IMHO , I don't think the MIPS (million instructions per second) figure is meaningful figure. Instructions take various times to complete. If you were running long op codes which can take 20+ cpu cycles, then whatever the MIPS is, it would be a higher MIPS number if only running instructions which only take a few cpu cycles. I think this is why nobody is replying to your question as it does not really have a answer.
4MB STFM 1.44 FD- VELOCE+ 020 STE - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - various clutter

http://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
http://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.
http://ataristeven.exxoshost.co.uk/Steem.htm Latest Steem Emulator

User avatar
mfro
Atari Super Hero
Atari Super Hero
Posts: 813
Joined: Thu Aug 02, 2012 10:33 am
Location: SW Germany

Re: 68000

Postby mfro » Sat May 30, 2015 5:06 pm

MIPS = Misleading Information to Promote Sale

But if you really want to know:

m68000 @ 8 MHz = about 1 MIPS
Atari Falcon = 3,84 MIPS
Atari Falcon DSP @ 32 MHz = 16 MIPS

Firebee (Freescale m5484 @ 264 MHz) : according to Freescale, up to 410 MIPS.

The last indication is a bit more meaningful since these are DMIPS (numer of instructions per second while running the Dhrystone benchmark). So this is measured using an at least somewhat meaningful program.

Freescale obviously managed to squeeze more than a single instruction/cycle out of the processor which is possible (with carefully handcrafted assembler) because of the EMAC extension.

alex
Retro freak
Retro freak
Posts: 10
Joined: Thu May 28, 2015 6:58 pm

Re: 68000

Postby alex » Sat May 30, 2015 7:34 pm

The 8 MHz 1 mip and 12 would be 1.5 MIPS? Greetings

User avatar
Xerus
Moderator
Moderator
Posts: 1233
Joined: Fri Dec 13, 2002 9:31 pm
Location: France

Re: 68000

Postby Xerus » Sun May 31, 2015 5:06 pm

I think the MIPS is the least reliable benchmark for comparing the machines together; the reason is that it has evolved over time !
An example, the 68030 at 16MHz (ex. Falcon) was 3.84MIPS but then the standard has changed and Motorala said later it was 5.76MIPS...

In short, it is likely that 1MIPS of 68000 8MHz no longer necessarily true :lol:

alex
Retro freak
Retro freak
Posts: 10
Joined: Thu May 28, 2015 6:58 pm

Re: 68000

Postby alex » Sun May 31, 2015 7:40 pm

You can reference tables but put that to one mip to 8 MHz, so I think the 12 MHz is 1.5 or 1.7. greetings

Hippy Dave
Atari Super Hero
Atari Super Hero
Posts: 515
Joined: Sat Jan 10, 2009 5:40 am

Re: 68000

Postby Hippy Dave » Sun May 31, 2015 7:55 pm

alex wrote:The 8 MHz 1 mip and 12 would be 1.5 MIPS? Greetings

Correct. MIPS was intended to be quantitative, but is relatively qualitative.
If a program appears to be more than 5% faster or slower, then you are
probably noticing a real difference. MIPS can be calculated by taking a
guess at this point.

My definition of MIPS is to make a 32 bit square root algorithm in C,
disassemble the code for clock cycles, then time the program for
your favorite number a million times. Presto... MIPS.

Discussions about MIPS are really about freedom of speech.

User avatar
Eero Tamminen
Atari God
Atari God
Posts: 1995
Joined: Sun Jul 31, 2011 1:11 pm

Re: 68000

Postby Eero Tamminen » Sun May 31, 2015 11:12 pm

Hippy Dave wrote:My definition of MIPS is to make a 32 bit square root algorithm in C,
disassemble the code for clock cycles, then time the program for
your favorite number a million times. Presto... MIPS.


My favorite binary numbers are 0 and 1.

User avatar
exxos
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 4933
Joined: Fri Mar 28, 2003 8:36 pm
Location: England
Contact:

Re: 68000

Postby exxos » Fri Jun 05, 2015 9:55 am

The OP still does not understand why MIPS is a meaningless figure..

Someone might be able to give a better example as 68000 instruction times is not my thing.. but.. For a general easy idea.

For example :

If a "add" instruction takes 8 CPU cycles, then assuming 8mhz CPU, then 8000000 / 8 = 1000000, So the CPU can do 1,000,000 of those instructions per second. or 1 MIPS.

Now what about a DIV instruction which could take 200 CPU cycles... then 8000000 / 200 = 40000, So the CPU can do 40,000 of those instructions per second , or 0.04 MIPS

I don't know about NOP fucntion, assume it takes 1 CPU cycle, no idea, if it did take 1 cycle, then MIPS would be 8 MIPS...

So whatever the manufacture quoted MIPS, it is the max speed with the fastest instruction the CPU can possibly do. The figure is pointless.

It is like having a car which has 1,000 MPH on the speedo. Sure if you dropped the car from the sky it probably would reach that speed. But in the real world of traction, typically what ? 60-100MPH ? Of course that assumes a straight line without any gosubs for burgers & icecream and such. So more like 40mph.

If that is to complicated, then try this one.. How fast can someone run .....?
4MB STFM 1.44 FD- VELOCE+ 020 STE - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - various clutter

http://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
http://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.
http://ataristeven.exxoshost.co.uk/Steem.htm Latest Steem Emulator


Social Media

     

Return to “Games - General”

Who is online

Users browsing this forum: Avanze and 4 guests