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Your laptop probably draws, what, 15W. Your old computer probably does not draw 15KW! - yes, I'm sure there will be old computers that do, and more, but since t
by tom_ 8y ago
Your laptop probably draws, what, 15W. Your old computer probably does not draw 15KW! - yes, I'm sure there will be old computers that do, and more, but since this article is about the Atari 800, I'm going to assume the discussion is about that sort of old computer, rather than something the size of a room that required a reinforced floor and your own personal account manager at the electricity company.
Modern hardware that I've got:
1. Mid-2015 13" Macbook Pro, mostly idle, battery charged, screen fully dimmed: 11W (16W with screen at full brightness)
2. My 2011 i7-2600K desktop: ~100W idle (packed away right now - but it's about that)
I happen to have my old Acorn junk set up right now, so here's some measurements from that:
1. BBC Master 128: 12W
2. BBC Micro model B: 25W
And some other Acorn peripherals. Add these figures to either of the above:
1. Acorn 6502 second processor: 5W
2. 5.25" disc drive: 2W (when in use)
3. Ancient early-80s monitor of unknown provenance: 50W
4. Acorn-branded CM8833: 85W
Looks like my favourite Acorn-branded monitor is actually pretty bad :( - however it's not actually drawing a huge amount more than the 2 x 27" monitor setup I have with my Macbook Pro, even though the pixels per watt isn't quite as good.
In fact: the overall power draw for BBC Master 128 setup vs Macbook Pro setup, both period-authentic, both (if not cutting edge for the time) up to the task of a good range of period-authentic workloads, is about the same! - and even if I was certain 1000x was an overestimate, this is still a bit of a surprise...
- mokus 8y agoIf you factor in that your MBP could probably comfortably emulate 100 6502s in real time, 1000x isn’t quite as severe an overestimate. Get the GPU in the game and, even with terrible warp utilization and cache efficiency, you still might be able to hit that 1000x for purely academic purposes on a desktop card with HBM (maybe 2500 real-time-emulated 6502s on a 250w system). Move to the microcontroller world, though, and 1000x is a vast underestimate. The main core in a current project of mine runs at 24 MHz and draws around 1.2 mW without even entering sleep. This system could probably emulate a Master 128 just fine in real time, for about 1/10,000x the power.
- tom_ 8y agoMy MBP can probably comfortably emulate 150 x 1 MHz 6502s in real time, but your average 6502-based system is a system, not just a 6502, and the Acorn stuff is no exception. There's a lot more to emulating it than just dealing with the CPU. The Master 128 runs at 2MHz. For each emulated microsecond you need to (broadly speaking) do at least 2 CPU updates, 2 VIA updates, and 16 bitmap bits/1 teletext glyph. 24MHz = 24 cycles per emulated µsec :( - good luck even squeezing the video output into that, let alone the other stuff. Rather you than me! (This also ignores handling the FDC, ADC, and ACIA. The devices accessed via the VIA will also take a bit of time to emulate...)
- liveoneggs 8y agoI'm talking more raspberry pi range than MBP, which is also 1000x more powerful. (or more; aka could probaly emulate all of the BBC Micros every sold at once)
- liveoneggs 8y agoa raspberry pi is 5W(?) at 100% cpu I think and can still emulate all of these machines with room to spare. My macbook pro is only drawing 15W because it also includes a monitor and keyboard and happens to be plugged in. Otherwise I can emulate a data center worth of these machines without drawing ANY additional power ;)