Just... No. Sure, having something off will cause less strain, but the MFR laser drill is arguably the most CPU friendly way to dig for ores in the game. And this is assuming sieving just one sort of item is the alternative. Sieving requires some sort of activator or blockgate to run it. It requires something to get stuff to put in it, which will be 1 or more pulverisers. Those need power, which is a bunch of calculations on it's own to get it there, let alone the choice of how you're generating power. And then the fuel for whichever RF maker you're using will take more effort to create.
Only issue for a laser is the power source. And yes, if you're just stacking dynamos, it's not going to go well, but we have many better options in the pack.
In the case of the laser drill, it's the power source that creates the lag.
Furnace-type generators need tree farms. Reactant dynamos with mob essence require a mob farm, so do TNT generators. Biofuel requires normal farms.
In the end, the chain of getting power to the laser drill to run would create just as much lag as a sieve. More even, if the sieve is on a slow clock,
whereas a typical sieve setup could run on just 1-2 generators.
The only power source I can see in the pack that wouldn't cause more lag than a slow/ish sieve, is a big reactor - but the sieve is capable of being so fast, even on a slower clock, that it outweighs that by turning it off most of the time - since it's not needed.
So, as I see it:
- A non-reactor powered laser would generate more lag when on than a sieve, arguably less than a sieve on a 1-clock though.
- A reactor powered laser would generate less lag while on than any moderate sieve setup. (although, I reckon AA + vacuum hopper would come close).
- A Sieve setup doesn't have to be on very often, unless it's on a really really slow clock, in which case, it wouldn't generate much lag anyway.
In the end, If you modify each system so they're generating the same amounts of materials (roughly), I don't think there'd be much difference in lag - if you're using Reactors for powering the laser. It would take so much infrastructure for the laser to catch up to a sieving system, that to even them out, you'd have to run the sieve so slowly it wouldn't generate almost any lag.
How about the original / second version of this from VSWE, both the creator of this sifting system, and of the mod itself? The lever goes on the Emitter, next to the receiver. The logic is such that "On high edge / on low edge, do the stuff, oh, and switch to the other edge". By putting the lever on the emitter, you can force it up into the high edge, and hold it there. That way, when the machine gets that high edge, it tells the emitter to turn off (low), but the lever is still on, meaning that "On low edge" cannot fire.
When you turn the lever off, the emitter is already off, and so the low edge can fire, restarting the clock.
There is no issue with the on / off switch. I personally think it's a little too overpowered for what it is, so don't use the clock like this, but will be setting up an SFM sieve system soon on either a 1 second clock, or with multiple block gates on one sieve, if that works.
That's what I though was happening, and it wasn't necessarily that it "doesn't work" (although I swear I saw it 'not working' in one of the youtube vids), it's that that is a really sloppy way of making a switch. It's also reversed.
I have OCD for system designs...
My system uses a redstone pulse, and only low edge, that way I can define exactly how many ticks between each run.
So it goes:
On Lever high edge OR on redstone emitter low edge | If lever is still on | Run stuff | Pulse the emitter for x ticks.
That way it runs every time the pulse turns off.
