Oh, my mistake.
I figured that when he compared an eight-core, 3 GHz tower to a two-core, 2 GHz laptop, that it would be significant if, say, the 2 GHz laptop performed a task nearly twice as fast as the tower, which technically has, at least in theory, six times the horsepower under the hood.
But since it's only seconds we're talking about, and not, you know, hours, you're of course right.
Except, half of all benchmark testing deals with things that take only a few seconds... photoshop benchmarks (PSBench) is a good example. When the G4s came out, and Adobe optimized photoshop for AltiVec, the PS 5.5 benchmarks that showed the G4 outstripping the G3s nearly twice as fast in Lighting Effects impressed many. The difference? A few seconds. But it represented a 100% increase in speed.
No, it isn't. Any slight thing can cause that kind of difference if the total time taken was a few minutes, and the difference was a few seconds. And that would only be on
identical machines.
However, as he's explained it, one took 7 seconds, and the other took 13 total.
Even then, memory timings that slight probably wouldn't make much difference, and
certainly wouldn't make anything he'd ever notice. Barefeats ran 667 MHz FBDIMMs in the new Mac Pros, and they performed identically to when they had 800 MHz FBDIMMs in them. And latency is even less important than that. Memory latency doesn't just apply to the beginning of an operation, adding a few seconds to the start. Even if it were (which is a ridiculous idea), it certainly wouldn't add in seconds. The only time it makes a difference is when something takes a reasonably long time, then you can start counting the difference in seconds.
Here, BareFeats investigated memory timings in the MacBook Pro.... one set of benchmarks in a long line of memory testing which has been going on for years (think AnAndTech, FiringSquad, Tom's Hardware, etc):
http://barefeats.com/mbpp03.html
The conclusion? Less than 1% difference most of the time.
If you want to read up about memory latency, you could try here, at Ars Technica:
http://arstechnica.com/paedia/b/bandwidth-latency/bandwidth-latency-1.html
You're absolutely correct, hard drive cache
is important. So long as you've got some. 512K is really enough. More doesn't help, especially over 2 MB.
And explain to me how you figure hard drive cache would make any difference at all in rendering, when all the data has likely been stored in RAM? Actually, since you've obviously read up on it so thoroughly, why don't you explain to me how hard drive caching works?
Cache only matters, first of all, for frequently used data... and only data that's already been accessed, save during things like burns which employs precaching. Rendering shouldn't even involve the hard drive.
The only time you'd ever use a hard drive in an application like, for instance, Photoshop (which obviously doesn't involve rendering) is when you run out of memory, and hit your scratch disks. That doesn't really even happen anymore when you've got 8 GB of RAM devoted to a task.
Cache helps for burst rate improvements... I can't think of much else. CPU L1 and L2 cache size matters. Hard drive cache size, not so much.
Cache size doesn't matter. Want to read about it?
http://www.tomshardware.com/reviews/understanding-hard-drive-performance,1557-5.html
I actually made a thread about that a month or so ago with that link.
https://forums.macrumors.com/threads/480423/
I saw a test years before between 2 MB and 8 MB. Same thing, only the 8 MB was often slower.
They of course only measured things that have to do with hard drives.. you won't find anything that has to do with rendering, I'm afraid.
