Gentoo Archives: gentoo-user

From: Stanislav Nikolov <stanislav.ltb@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Better CPU for compiling with gcc
Date: Tue, 10 Nov 2015 19:07:43
Message-Id: 5642406E.2080808@gmail.com
In Reply to: Re: [gentoo-user] Better CPU for compiling with gcc by Alan McKinnon
1 On 11/10/2015 08:55 PM, Alan McKinnon wrote:
2 > On 10/11/2015 20:37, Stanislav Nikolov wrote:
3 >>
4 >> On 11/10/2015 08:17 PM, Mick wrote:
5 >>> On Tuesday 10 Nov 2015 17:47:08 Stanislav Nikolov wrote:
6 >>>> Dear Gentoo users,
7 >>>> I'm building a new PC. I have a budget of ~$550-$650. No GPU, no special
8 >>>> case (I may use a card box), not even a hdd or ssd. So, as you can see,
9 >>>> it's pretty much "get the best CPU and mobo/ram that are compatible with
10 >>>> it". The problem is, which is the best one. By "best" I mean to compile
11 >>>> shit fast. My laptop with 3rd gen i5 compiles firefox for 40 minutes on
12 >>>> average.
13 >>>>
14 >>>> The most expensive Intel CPU is the skylake i7-6700k. But is it the best?
15 >>>> Is there something from AMD that will perform even better? I can't find
16 >>>> any benchmarks with AMD/Intel CPUs. And how much does the mobo matter?
17 >>>> Will a cheap $30 400W PSU power that thing?
18 >>>>
19 >>>> Thanks
20 >>> I don't (yet) own a i7-6700k, but my 6 year old laptop with (1st generation)
21 >>> i7 Q720 @1.60GHz takes slightly less than yours:
22 >>>
23 >>> Sat Oct 3 14:35:40 2015 >>> www-client/firefox-38.3.0
24 >>> merge time: 36 minutes and 53 seconds.
25 >>>
26 >>> Fri Nov 6 09:10:06 2015 >>> www-client/firefox-38.4.0
27 >>> merge time: 38 minutes and 8 seconds.
28 >>>
29 >>>
30 >>> In contrast a year old AMD A10-7850K APU is significantly faster:
31 >>>
32 >>> Sat Oct 3 19:40:48 2015 >>> www-client/firefox-38.3.0
33 >>> merge time: 17 minutes and 42 seconds.
34 >>>
35 >>> Fri Nov 6 08:41:02 2015 >>> www-client/firefox-38.4.0
36 >>> merge time: 18 minutes and 18 seconds.
37 >>>
38 >>>
39 >>> I would also be interested to see compile times of more modern i7s and FXs,
40 >>> but bear in mind that in single core operations Intel is these days
41 >>> significantly better than AMD.
42 >>>
43 >> So, I shouldn't prepare for a 8x times faster compile time... :(
44 >>
45 >
46 >
47 > I can't help but think you are approaching this from the wrong perspective.
48 >
49 > Why exactly are you using compile times as your sole criterion? Are you
50 > building a compile farm for Ubuntu? Running continuous integration tests
51 > for LibreOffice [on a $600 budget in a cardboard box :-) ]?
52 >
53 > Or do you want emerge world to get it over with quicker?
54 >
55 > If the latter, you better rethink your priorities. In computing terms,
56 > compilation is a rare event; launching apps is a common event; and
57 > writing to the disk happens all the time. Optimize for the common case.
58 >
59 > A CPU never works in isolation, it is always part of a much larger
60 > system, like disks, RAM and all possible kinds of I/O. The best CPU on
61 > the market plugged into a POS motherboard will perform on emerge world
62 > like a piece of shit - it will follow the weakest link.
63 >
64 > If you want to build a compiling machine, buy the best collection of
65 > stuff that works together well and still fits the budget. If you want a
66 > machine that you can use and be happy with, ignoree the temptation to
67 > must have the biggest baddest fastest CU (you will never get to use all
68 > that big bad fast) and invest rather in gobs of RAM and an SSD. Remember
69 > that apps are launched many times more than they are compiled. Or put
70 > another way, sacrifice compilation times t get something you can use.
71
72 8GB of RAM are waaay more than I use daily (several firefox tabs, nvim = 2Gb max), I have a pretty fast SSD too. Even buying 8GB RAM and a brand new SSD, I have > $450 left. Can I buy a AMD CPU that will get the job done faster than 6700k and/or cheaper?

Replies

Subject Author
Re: [gentoo-user] Better CPU for compiling with gcc Alec Ten Harmsel <alec@××××××××××××××.com>
Re: [gentoo-user] Better CPU for compiling with gcc Alan McKinnon <alan.mckinnon@×××××.com>