On Tue, Apr 25, 2017 at 11:10:26AM -0600, Alan Feuerbacher wrote: > > Interesting points. Until recently I didn't concern myself with such speeds > much, but used all default settings. I'm now retired and have time on my > hands, and am getting a new CPU, MB and memory. I've been a bit confused by > all the advertising numbers and hype, but think I understand what's going > on. > > My new Intel CPU (i7 7700K) is spec'd at 2400MHz memory speed, but can be > overclocked. Apparently it makes little sense to buy memory that is spec'd > at a higher speed than the CPU is spec'd at, but advertising hype touts > stuff like "3600MHz memory!" I stumbled on a bargain at Amazon for 3333MHz > memory (less money for Prime members than lower spec'd memory for non-Prime > members), so now I have an ASUS MB spec'd at 3866MHz, memory at 3333MHz and > CPU at 2400MHz+. I don't have a clear idea what to do with all this new > technology. > > It would be interesting to play with various memory speed settings as I > compile LFS programs over the next few weeks. > > Comments? > > Alan > First, make the most of having time on your hands - the rest of us will be doing all we can to encourage you to contribute, and then suddenly you will have less time on your hands ;-)
But seriously, playing with new/current hardware is always interesting. I've had two iterations of A10 Kaveri hardware (ok, you intel guys can snigger at that) - on the first one it was fun and games getting it to run the memory at its rated speed. Eventually that machine died (motherboard or capacitor fault, I think). The replacement worked briefly, then became unreliable - in the end I swapped in the memoryfrom the broken one and it now runs ok. An A10 is an APU (integrated graphics), for which faster memory is supposed to improve the graphics (no idea if that is general, or only for gamers). BUT: memory is not just the clock, it's the memory timings https://en.wikipedia.org/wiki/Memory_timings and various DIMMs from different manufacturers might have different timings. And at the end of the day it is questionable how much real difference the variations will make. For semi-recent but not i7 hardware, I would be extremely happy to get a 5% speed improvement :) But like Bruce, I find that each new toolchain makes the build slower. We are close to the point where a desktop i7 is the minimum for comfortable compile times. I hope to try a Ryzen soon-ish, but I need to change monitors before I do that. For me, my basic test - on a booted LFS system - is to rerun pass 1 binutils. I haven't played with memory settings beyond persuading htat original A10 to use what it had, but I also use this to compare the times with various cpufreq governors. If the memory speed does actually make a difference, I'm sure it might show upo there - but for that I am dubious about how repeatable the results are (unless you use an rt kernel). Whatever, find something to explore, and have fun. ĸen -- Error: ( : 1) not enough arguments Don't you just love Tiny scheme ? -- http://lists.linuxfromscratch.org/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page Do not top post on this list. A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? http://en.wikipedia.org/wiki/Posting_style
