It seems my assumptions were completely incorrect... there
are memory limits when using a non-Extreme processor. I popped in the Core i7 920 earlier and the default (and maximum) memory speed was DDR3-1066, with the only other option being DDR3-800. Essentially, that means the memory multipliers are locked to 6x and 8x, and the only way to increase the memory speed is to increase the Base Clock.
So, bumping the Base Clock to 166MHz will boost the memory to DDR3-1333. I really couldn't imagine seeing the BCLK going much higher than that for most people, though. I did a quick test earlier with a BCLK of 167MHz and the memory speed at DDR3-1333 and it seemed incredibly stable. I haven't tested out the CPU's top-end overclock of 3.32GHz though (assuming most people wouldn't go above 166MHz BCLK, as I mentioned), but I will try to tackle it soon.
I usually create animations at 30 frames per second. Each frame counts as a single render. If I create a 30 second animaiton, that equates to 900 frames I have to render. Those 3 or 4 seconds saved per frame add up to an hour being shaved off of my render times. And that's just for a short 30 second animation. Imagine how much time a 30 minute animation would save.
That's true and I understand that, but as I mentioned in the article, my conclusions were based around the regular consumer... and you are definitely not a regular consumer with workloads like that. I did mention before (if not in this article, previous ones) that faster memory can benefit the professionals if workloads can take days to accomplish, because a few hours saved is going to be appreciated I'm sure.
In our results though, I really didn't see definitive evidence that faster memory guarantees a faster rendering time, regardless of how large the workload is. As you can imagine, we don't have access to these huge workloads, so we can only use what we have here. The most in-depth workload I could find on Autodesk's sample DVDs was the Dragon scene, which
might be a good test for memory, as it would take around 30 minutes to render a full 60-frame 1080p scene, although it would require a lot more time on my part. I'll definitely consider a follow-up to this article, taking more intensive workloads into consideration. Thanks for the input, I appreciate it.
Thanks for your reply. I am still not sure however. I did read the article but you used a Core i7 965 where the CPU and memory multipliers are unlocked and adjustable for most DDR3 memory, so I don't know what will happen with a 920 - which is what most of us will be buying.
I mentioned the answer already, and yes, you'll be unable to take full-advantage of what the memory kit offers with your i7 920. As seen in the article though, you are very, very unlikely to notice any speed increase with the full DDR3-1600 speed though, so in a way, you won't be ripped off of any real performance. You did kind of throw your money away with getting a bigger kit though, sadly.
Does it make automatic corrections to somehow find a new optimum performance or just continue blindly.
It will just adjust itself to DDR3-1066, since with the given restrictions, it will be impossible for it to go any higher. The default memory clock in the CPU is 133MHz and the default memory multiplier is 8x, so it will result in DDR3-1066 at boot.
The question is what DDR3-FFFF means. Does is mean that FFFF is the limiting UPPER frequency (what I assume), or does it work ONLY AT that frequency and will have trouble if the system BIOS "expects" a lower frequency.
That figure is the max-supported frequency of that kit of RAM. Slower speeds will be programmed into the SPD, and that's what it usually defaults to at boot, unless the CPU comes into play and has something to say. The best thing is to just go into the BIOS and manually set your settings to make sure it boots with the correct frequency and timings.
As for plugging in the memory and it "just working"... that doesn't really happen with high-performance RAM. If you are running anything higher than DDR2-1066 or DDR3-1066, and never set anything in the BIOS, chances are it's running slower than stock. You can check the memory tab in CPU-Z to see if it's running at the correct frequency. You would just take the raw frequency, multiple by two to get the proper DDRx-FFFF rating.