Just to add to the Original question, the real difference between a 030 @ 50Mhz & an 040 @ 50Mhz = Some Years of Progress from Motorola.
Any CPU without an FPU (Floating Point Unit) is gunno take far far longer to calculate Floating Point Instructions. These are used by Programs such as CAD Packages, DTP where Image manipulation is required & more specifically, 3D Modelling.
So taking the more common Motorola CPU's used by CBM for their range of Amiga puters, here they are in rough running order of speed.
68000, 68020 & 68030. I pause here because all these CPU's never came with onboard FPU's, but you could either fit a PLCC or a PGA Socket to take the required kind of FPU to be fitted.
Then we have the 680040 & the 68060. These came in a variety of speeds & also a variety of flavours. Speeds on the 040 were usually 25Mhz, 33Mhz & 40Mhz. 68040's were rare at 50Mhz due to Heat constraints within the silicon for using 5v on that Die size. When the 060 was released with a new Die Size, the Voltage was also dropped to 3.3v, meaning a 50Mhz 060 is actually a much much cooler CPU than a 40Mhz 040 & absolutely spanks the 040 @ 40Mhz when it comes to CPU & FPU calculations.
Going back to the Varieties, these were annotations used for what I class as "Deprived" CPU's, as they had either no FPU & worse still an MMU (Memory Management Unit)
Back in the traditional Days of Amiga, SCSI was always favoured because of the way SCSI Works. It off-loads all the CPU Transfer calls required by the hard drives to the hard drive controller itself. IDE does NOT do this on an Amiga. An MMU was required by "Unix" on the Amiga & the only after-market program I know of that required an MMU was "Giga-Mem". This was a Virtual-Memory program for the Amiga, where it used Hard Drive space as "Virtual-Ram". Try using that program on IDE drives instead of SCSI; - er...."Hello clockwork computer" when the Virtual Ram was being used! :roll:
EC & LC annotations in the CPU part number mean it`s a CPU that probably failed all full Tests when Soak Tested after the Silicon Wafers had been processed into their relevant Part. For Example, if a batch of 50Mhz 060`s were made, they would all be tested for CPU, FPU & MMU calculations. If the MMU failed, they went out as an LC marked CPU - (Low Cost). If the FPU failed, they were shipped as EC CPU`s or as in the case of the A4000, the 030's were always Badged EC030 anyways & the 030 never had an Internal FPU. CBM were numbering But there was provision for either a PLCC or PGA Socket to attatch an FPU.
Whilst Soak testing the CPU's, they were also checked for operating speed. Purer slices of Silicon would run faster & hence the variety of speeds. The faster & more feature rich ones being more expensive of course.
On top of this, the market also has demands for supply. On some occasions, you might be lucky to have an EC060/75 that will Under-clock to say 60Mhz & the FPU works. That makes it a faster CPU than an 060 @ 50Mhz.
Hope this all helps & makes sense as to which type of CPU is better to have. :-)
