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Author Topic: Which affects speed more? Processor or RAM?  (Read 7457 times)

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Offline Ilwrath

Re: Which affects speed more? Processor or RAM?
« Reply #14 on: March 03, 2010, 10:51:01 PM »
Well, it's all depending on the type of system we're talking about, and where the bottleneck currently is.

Taking an Amiga 1200, for example, it's completely hobbled when it can only access Chip RAM.  Adding some 32-bit Fast RAM makes a _HUGE_ difference.  If you test an A1200 with an '030 card with 2MB Chip/0MB Fast and compare typical processing vs. an A1200 with the stock '020 but a 8MB 32-bit board...  The one with the '020 and Fast RAM will win that fight most of the time.  Of course, add a stick of Fast RAM to that '030 board, and then it's easily back on top.

So...  For old school Amigas...  Fast RAM helps.  Faster CPU with on-board Fast RAM helps more.  (But adding just a faster CPU, without giving it a 32-bit path to Fast RAM, doesn't help that much.  [unless, as stated, you manage to fit all the instructions into cache, which is VERY UNLIKELY, as the '030 had something like 256 _BYTES_ of cache...]  That is why most CPU expansions also include Fast RAM.)  

More modern systems are a little harder to figure out.  But, typically, you want to find the bottle-neck and increase that.  (Sometimes it's the CPU speed, sometimes it's the RAM speed, and sometimes it's swapping a bunch, which means RAM size.)
 

Offline Tenacious

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Re: Which affects speed more? Processor or RAM?
« Reply #15 on: March 03, 2010, 10:55:25 PM »
Back from dinner.

To complete the thought, 16 bit accelerators are harder to come by today.  The Supra Turbo 28 Mhz was the only one worth anything.  It was very good!

32-bit accelerators for 16-bit amigas are spendy and need 32-bit ram to be useful.

Which Amiga are you talking about?
« Last Edit: March 03, 2010, 10:59:11 PM by Tenacious »
 

Offline ElPolloDiabl

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Re: Which affects speed more? Processor or RAM?
« Reply #16 on: March 04, 2010, 12:00:38 AM »
Amiga accelerators are affected by slow ram. e.g. I had an A2000 with 68030 and 2MBs of 32-bit ram on the accelerator. Also there was 4MB of 16 bit ram in a zorro slot. The machine would fly on while it had that 2MBs available. If I turned off the CPU slot ram the machine would slow down... a lot. If you turn off all extra memory and it has to share the chip RAM memory there is an even bigger slow down, only slightly faster than a stock unexpanded system.

Starting with an 68040 (8k cache) you start to notice the performance benefit of the cache memory. Processors nowadays wouldn't be any faster if they didn't have very fast and adequately sized level 1 cache memory. Level 2 cache memory larger, but slower only adds about 15% more speed.
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Offline runequesterTopic starter

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Re: Which affects speed more? Processor or RAM?
« Reply #17 on: March 04, 2010, 12:18:21 AM »
Quote from: Tenacious;546054
Back from dinner.
 
To complete the thought, 16 bit accelerators are harder to come by today. The Supra Turbo 28 Mhz was the only one worth anything. It was very good!
 
32-bit accelerators for 16-bit amigas are spendy and need 32-bit ram to be useful.
 
Which Amiga are you talking about?

Ultimately a 1200, but cheap 600s show up reasonably often as well
 

Offline delshay

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Re: Which affects speed more? Processor or RAM?
« Reply #18 on: March 04, 2010, 12:26:32 AM »
SWIV is a great game and showed on a standard amiga when loading from disk during game play showed littel sign of slow-down during disk access if i remember correctly.
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Offline Tension

Re: Which affects speed more? Processor or RAM?
« Reply #19 on: March 04, 2010, 01:14:38 AM »
Either way, an accelerator wont be any use unless you put some RAM in it.

Got an Apollo 1240 for the 1200 for new when I was a kid.  Didn't make any difference in speed til I put a 16MB SIMM in it.  Wow what a difference!

Offline matthey

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Re: Which affects speed more? Processor or RAM?
« Reply #20 on: March 04, 2010, 01:27:26 AM »
Quote from: Fanscale;546061

Starting with an 68040 (8k cache) you start to notice the performance benefit of the cache memory. Processors nowadays wouldn't be any faster if they didn't have very fast and adequately sized level 1 cache memory. Level 2 cache memory larger, but slower only adds about 15% more speed.


Bingo! Even the C= A3640 performed reasonably well using only motherboard memory because of the cache and small Amiga programs. It generally outperformed a 50MHz 68030 with faster memory and 2x the processor speed. It had a lot to do with the cache. It is more important to have some fast ram instead of chip ram though. The CPU can be slowed to as much as 1/2 speed without fast ram as the custom chips steal CPU cycles.
 

Offline Cammy

Re: Which affects speed more? Processor or RAM?
« Reply #21 on: March 04, 2010, 02:38:47 AM »
I just did a few speed tests using SysInfo on some of the Amigas here. These are the results:

A600 (2MB Chip, No FastRAM)
526 Dhrystones
0.54 MIPS

A600 (2MB Chip, 2MB PCMCIA SRAM)
699 Dhrystones
0.72 MIPS

A1200 (2MB Chip, No FastRAM)
1092 Dhrystones
1.13 MIPS

A1200 (2MB Chip, 2MB PCMCIA SRAM)
840 Dhrystones
0.87 MIPS

A1200 (2MB Chip, 8MB FastRAM)
2819 Dhrystones
2.94 MIPS

Some RAM makes the Amiga perform faster, other RAM can slow it down.
A1200 030@28Mhz/2MB+32MB/RTC/KS3.1/IDE-CF+4GB/4-Way Clockport Expander/IndivisionAGA/PCMCIA NIC
A1200 020@14Mhz/2MB+8MB/FPU/RTC/KS3.0/IDE-CF+2GB/S-Video
CD32 020@14Mhz/2MB+8MB/RTC/KS3.1/IDE-CF+4GB
A600 030@30Mhz/2MB+64MB/RTC/IDE-CF+4GB/Subway USB/S-Video/PCMCIA NIC/USB Numeric Keypad+Hub+Mouse+Control Pad
A500 000@7Mhz/512kB+512kB/ROM Switcher/KS3.1+1.3/S-Video

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Offline whiteb

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Re: Which affects speed more? Processor or RAM?
« Reply #22 on: March 04, 2010, 03:29:35 AM »
In an Amiga 4000 for example.

Lets hypothetically say, the Mainboard has 16MB of ram, with a Cyberstorm 060, WITHOUT any ram.

That is going to CHOKE beyond belief while the 060 waits for the system bus to access the ram on the mainboard.  Then we add the ram to the 060, fully populate the Cyberstorm board with 128MB of ram, at which point it no longer needs to wait, the 060 with ram SCREAMS with speed, it only needs to access the main system to access the Custom chips, and/or IDE. (That is also why Cyberstorms have their own SCSI).
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Offline Tenacious

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Re: Which affects speed more? Processor or RAM?
« Reply #23 on: March 04, 2010, 03:40:21 AM »
Cammy wrote:

A1200 (2MB Chip, 2MB PCMCIA SRAM)
840 Dhrystones
0.87 MIPS

A1200 (2MB Chip, 8MB FastRAM)
2819 Dhrystones
2.94 MIPS

Some RAM makes the Amiga perform faster, other RAM can slow it down.[/QUOTE]

PCMCIA SRAM is Fast Ram but only 16-bits wide (still great for an un-accelerated A600).  For a performance boost, a 1200 needs 32-bit fast ram, with or without an accelerator.
 

Offline Cammy

Re: Which affects speed more? Processor or RAM?
« Reply #24 on: March 04, 2010, 04:44:55 AM »
Isn't that what I just proved?
A1200 030@28Mhz/2MB+32MB/RTC/KS3.1/IDE-CF+4GB/4-Way Clockport Expander/IndivisionAGA/PCMCIA NIC
A1200 020@14Mhz/2MB+8MB/FPU/RTC/KS3.0/IDE-CF+2GB/S-Video
CD32 020@14Mhz/2MB+8MB/RTC/KS3.1/IDE-CF+4GB
A600 030@30Mhz/2MB+64MB/RTC/IDE-CF+4GB/Subway USB/S-Video/PCMCIA NIC/USB Numeric Keypad+Hub+Mouse+Control Pad
A500 000@7Mhz/512kB+512kB/ROM Switcher/KS3.1+1.3/S-Video

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Offline matthey

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Re: Which affects speed more? Processor or RAM?
« Reply #25 on: March 04, 2010, 04:48:37 AM »
Quote from: Cammy;546084

A1200 (2MB Chip, No FastRAM)
1092 Dhrystones
1.13 MIPS

A1200 (2MB Chip, 2MB PCMCIA SRAM)
840 Dhrystones
0.87 MIPS

Some RAM makes the Amiga perform faster, other RAM can slow it down.


That is odd and rare. That must be some slow SRAM. The OS probably gives the SRAM a higher priority than chip ram as normal but it must be slower. You need ChipMemFirst for this 1200 ;). Lot's of memory on the Amiga can actually be slower after it's fragmented unless running TLSF mem or similar. There is a longer memory list to transverse.
 

Offline Damion

Re: Which affects speed more? Processor or RAM?
« Reply #26 on: March 04, 2010, 05:03:32 AM »
Quote from: matthey;546103
That is odd and rare. That must be some slow SRAM. The OS probably gives the SRAM a higher priority than chip ram as normal but it must be slower. You need ChipMemFirst for this 1200 ;). Lot's of memory on the Amiga can actually be slower after it's fragmented unless running TLSF mem or similar. There is a longer memory list to transverse.



IIRC, PCMCIA bandwidth on the A1200 is something like 2-3MB/s, which is pretty damn slow even compared to chipram.
 

Offline stefcep2

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Re: Which affects speed more? Processor or RAM?
« Reply #27 on: March 04, 2010, 06:41:47 AM »
The simple answer is this:

With A1200, fast ram will double the speed of most tasks.  A cpu card with no fast ram will only speed up cpu-intensive tasks.  A cpu card with fast ram on it will make the biggest speed improvement.  

If you want to do things like play games, mess about with 2D paint and animation software, then just get a cheap RAM card and a compact flash card and stick whdload on it with a preconfigured Workbench environment like ClassicWB (use the version thats made for an A1200 with a fast ram only.)
 

Offline gertsy

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Re: Which affects speed more? Processor or RAM?
« Reply #28 on: March 04, 2010, 01:17:05 PM »
I reckon its the quaility of the cut.
 

Offline Amiga_Nut

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Re: Which affects speed more? Processor or RAM?
« Reply #29 from previous page: March 05, 2010, 03:36:09 AM »
I think some confusion as to why RAM 'increases' the speed of a PC or Mac and therefore the question here. Also PCs do not have Chip/Fast/32bit RAM debacle too.

I will bow to the superior Amiga knowledge about the merits of CPU and various types of RAM on every Amiga model produced.

But as far as PCs and Intel Macs go...they are running bloatware....adding more memory just alleviates the seriously bad code running on your CPU box. So...if you have Windows 7 and 1Gb of RAM and simply shove in a stick of 2Gb memory to make 3Gb (negating a speed increase due to dual channel mode) the only reason your speed 'increases' is because your bloatware OS has more room to stretch it's bingo wings code ;) I suppose some Amigas will benefit from RAM over CPU in some cases but overall it's not quite as general a problem.

You can run XP quite happily on 100mhz if you have 256mb of RAM...but 64 or even 64mb on 300mhz is useless and 'slower'

What you should also factor in though is replacing hard drives with state of the art lightning fast solid state Compact Flash drives on any AGA machine too....this also makes a massive difference on PCs and will improve your perceived speed on an Amiga too I guess. Some companies produce 2.5 IDE hard drive sized solid state drives with the SATA/PATA IDE connectors all fused in a handly little plug in replacement box which work a treat on the A1200/600 and A4000.