90D. Well that’s disappointing for us 7D2 users

Started 2 months ago | Discussions thread
OP IR1234 Senior Member • Posts: 1,543
Re: DIGIC8 is multicore?
1

RLight wrote:

IR1234 wrote:

Sharlin wrote:

IR1234 wrote:

So specs don’t seem to show dual cards or dual DIGIC, so the 90D isnt any sort of 7D2/80D compromise. It’s just an updated 80D.

What would they need dual processors for if one DiGIC 8 can do 32MPix @ 10fps? Sensor readout speed is almost certainly a bottleneck at such extreme throughput that out of all Canon cameras only the 1DX 2 has achieved previously! The throughput of the 7D2, with its dual processors, is just 200 Mpix/s. In real-world engineering you can't just make one part of a system faster and expect the whole thing to speed up.

Dual processors is more than MP throughput. If you take our 6d2 into the field where we usually have the 7d2 or 7d, you can feel the af very slightly start to bog down as the processor gets busy shuffling data around. The UI takes a real hit when the camera is busy, even just changing a Q setting let alone image review. The camera just does not have the same snappy feeling the 7d or 7d2 has.

Dual processors also handle things like secondary card resizing, eg L on cf, and S1 on sd, absolutely flawlessly.

Just some food for thought... After playing with two DIGIC8 Canon's now (M50 and EOS R), I'm pretty sure they're multicore. Why? Responsiveness of the camera while it's writing out or AF'ing, etc. You can't get that with just more speed (ghz) and properly using nice values on an OS implementation level. Well, usually anyways.

I noted it was a HUGE jump vs DIGIC7 and before.

Odds are DIGIC8, and newer chips, like smartphone CPUs these days are at least dual core, if not more.

You used two CPUs back in the day on big server rigs because of the need to do it in the same way 1DX models and 7D II etc have. Multicore CPU implementations have (largely) obsoleted this for consumer use.

Think about it for a minute. New DIGIC8 Canon's have the new live sync to your smartphone mode. On mirrorless (like the M50 and R), they have to handle both the presentation of your data on an LCD/EVF (which isn't a problem on an OVF DSLR as that's all old school no electronic presentation, merely AF overlay) and AF calculations, image capture and compression, metering, etc etc etc.

IMO, DIGIC8 is multicore. The data throughput (14x32MP==448mp/sec) also says they didn't just double the ghz somehow (as that's hard to do)... That tells me DIGIC8 is probably a dual core chip (1DX II does like what, 16*20/2=160mp/sec per core) as it's got a slightly higher effective mp/sec which per core if it has two at around 224mp/sec per core if two cores... They didn't just get double the data rate out of thin air.

Make sense?

So yes, dual processors can make a big difference on these cameras when you push them. And we push them.

I see where you're going with this, but, I haven't read anything that DIGIC8 is multicore, and I would assume that if Canon had gone that route, then they would be the first to include it in their literature. Which they haven't.

I'm not sure your analysis is correct though. 14x32 (448) vs 16x20 (320) is a significant speed bump for sure, but the 1DX2 isn't using 2 processors for that speed. That extra cpu will be handling AF and things like compression. Same goes for the 7D2 and 5D4.

So yes, you will see an improved performance on the DIGIC8 cameras, but probably not as much as you think.

You also have to remember that DIGICs are probably less processor and more ASIC. An ASIC will totally absolutely destroy any cpu on a given task. Which is Canon have their own line of processors and aren't using something like an Arm Cortex. You'll also note how Sony have their own BIONZ processors. Again, despite access to an arsenal of processors, they have their own line of processors, so again the DIGIC and BIONZ will be a cross between a processor for general purpose cpu activity like AF, and a number of ASICs.

For reference, my Macbook here has a quad i7 2.7GHz, and at full tilt with something like GraphicsMagick it can resize 8 20MP images per second to 640x. It wind's up it's fans and is really quite impressive. My Canon 7D2s can do exactly the same job, maybe only 7 images per second, and they have no fans, don't get hot, and carry on shooting as if nothing is happening. There is no way Canon have developed a processor as fast as the hundreds of billions Intel have spent to develop and build an i7. So some of these functions are most certainly ASICs.

And as a guess, it's why you really don't see many updates addressing too many baseline features. IIRC, you can't really update an ASIC.

Also, it's really not that easy for some of these jobs to be put across multiple cores or multiple processors. Generally, programmers have wimped out of fully developing software to run across multiple cores/processors (however, my latest is gotcha is the Debian installation of graphicsmagick on a Raspberry Pi does seem to use all the cores, which is really strange, need to investigate that more).

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