[CentOS] DDR2 compile times (was Re: segfaults with 8 gig of ram)

Thu Mar 29 14:40:52 UTC 2007
Peter Gross <pag at nanosec.com>

tblader wrote:
> Hello All.
> Below are some compile times for 2.6.20 on an fx-62
> running Centos64 with various 2 gig sticks of
> dual channel ram (See previous posts with subject
> of 'segfaults with 8gig of ram' for more details.)
> 
> It seems dual channel will compile a kernel faster,
> but only gained around 30 seconds over 20 minutes.
> Below are the shortest/longest compile times of
> several compiles done over the weekend.
> 
> Compile consisted of make menuconfig (save .config)
> time make dep clean bzImage modules
> 
> 
> 2 sticks dual channel @800mhz
> 10 samples
> ================================
> real 791.46
> user 664.10
> sys 93.85
> 
> real 799.88
> user 665.30
> sys 93.87
> 
> 
> 4 sticks dual channel @400mhz
> 5 samples (before it hurled booting)
> ================================
> real 876.19
> user 712.98
> sys 116.18
> 
> real 846.06
> user 710.16
> sys 115.42
> 
> 
> 
> 3 sticks single channel @800mhz
> 6 samples
> ================================
> real 815.74
> user 673.73
> sys 108.30
> 
> real 822.95
> user 674.32
> sys 108.62
> 
> 

I am putting together a pretty high-end workstation and originally had 
ordered 2gb sticks. Here's my [main] hardware specs:

Abit AB9 QaudGT motherboard
Intel Core 2 Duo E6600
Seasonic M12 PSU
3 Seagate 250gb SATA II disks

Since my main goal is to run VMWare Workstation with host OS Centos 5 
(when it comes out), I was originally interested in using 8gb memory. 
But after posting the following thread on the Abit motherboard forums, I 
discovered that the Intel P965 Express chipset does not fully support 
PC6400 (800) DDR2 memory:

http://forum.abit-usa.com/showthread.php?t=121720

So I returned that memory and went with 4 1gb sticks of low latency 
(4-4-3-8) memory instead, trading memory capacity for performance.