memory bandwidth

[Cyprian]

After googling I found few very interesting memory bandwidth benchmarks:

A1200 benchmark 1
chip readl 1066.6ns 3.8MByte/s
chip writel 1064.1ns 3.8MByte/s

A1200 benchmark 2
chip $00050000 readl 1139.8 ns normal 3.3 * 2^20 byte/s
chip $00050000 writel 570.5 ns normal 6.7 * 2^20 byte/s

A1200 benchmark 3
chip $00170000 readl 1090.0 ns normal 3.7 * 10^6 byte/s
chip $00170000 writel 720.2 ns normal 5.6 * 10^6 byte/s

F030 benchmark
Linear 32bit read (ST-Ram) 5.893 MB/s
Linear 32bit write (ST-Ram) 8.171 MB/s

It seems that, not only Falcon suffers from memory bandwidth bottleneck. And we can see that, Falcon with 16Mhz bus 16bit wide have more or less the same memory bandwidth like Amiga1200 with 14Mhz bus 32bit wide...

[ppera]

Yeah. But Amiga's bus is more contended.

[Cyprian]

What do you mean by 'more contended'?

[alexh]

There are more things on the bus requesting memory than just the CPU

[Cyprian]

Thx alexh

Yes, on both machines video dma was turned on. And consumption memory bandwidth was more or less the same.

Falcon:

640x480 4bits 60Hz noninterlace - VGA 16c (Ref : F030 VGA 16c) :
32bit read (ST-Ram) 5.893 MB/s
32bit write (ST-Ram) 8.171 MB/s

640x480 8bits 60Hz noninterlace - VGA 256c (Ref : F030 VGA 16c) :
32bit read (ST-Ram) 4.488 MB/s
32bit write (ST-Ram) 6.188 MB/s


Amiga:

640×480 6bits 63Hz noninterlace - Euro72 63Hz 6bits:
32bit read (chip) 3.8 MB/s
32bit write (chip) 4.7 MB/s

640x400 6bits 60Hz interlace - NtscHighreslaced 60Hz 6 bits:
32bit read (chip) 3.7 MB/s
32bit write (chip) 5.6 MB/s

[Frank B]

The Amiga Chip RAM bus is 32 bit on the 1200 but it only runs at 7 mhz.
The data cache on an 030 doesn't work on chip RAM either. The Falcon is faster than a stock 1200. Both cool machines though

[Cyprian]

Indeed, I like both Falcon and A1200.

[Cyprian]

I've just found very interesting topic on comp.sys.amiga.programmer

Someone in 1993 did various tests on real stock machines A1200 and Falcon - no fast ram, no any accelerators.
The outcome is that, Falcon is about 40% faster than A1200.

F30-A1200 benchmarks
Definitely must see it

[DarkLord]

Us Falcon owners were not surprised...