JeeLabs: Speedy Raspberry

The Raspberry Pi is an amazing little board, with an amazing amount of power and functionality at an incredible price – it’s probably fair to say that our technology geek’s world will never be the same again, now that we have the RPi.

But it’s no speed monster…

Sometimes during development, it really gets in the way – especially when you’re used to working on a modern fast laptop, which is some 20 times faster (and that’s per-core).

So I decided to overclock one of my RPi’s, and see what it does. Overclocking in Raspbian is trivial with the standard raspi-config utility:

Just go to the Overclock section, and pick one:

I went for the fastest there is, but decided to run a 2-hour test to make sure it really works. Turns out that someone has already done all the work, and even created such a stress test:

root@raspberrypi:~# ./overclock-test.sh 
Testing overclock stability...
reading: 1
945+1 records in
945+1 records out
3965190144 bytes (4.0 GB) copied, 352.455 s, 11.3 MB/s
reading: 2
[...]
reading: 10
945+1 records in
945+1 records out
3965190144 bytes (4.0 GB) copied, 358.522 s, 11.1 MB/s
writing: 1
512+0 records in
512+0 records out
536870912 bytes (537 MB) copied, 95.2065 s, 5.6 MB/s
writing: 2
[...]
writing: 10
512+0 records in
512+0 records out
536870912 bytes (537 MB) copied, 83.4848 s, 6.4 MB/s
./overclock-test.sh: line 18:  2414 Terminated
              nice yes > /dev/null
CPU freq: 1000000
CPU temp: 58376
[    5.217175] Registered led device: led0
[    8.943589] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
[    9.418819] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
[   19.181046] smsc95xx 1-1.1:1.0: eth0: link up, 100Mbps, full-duplex, lpa 0x45E1
[   19.431053] bcm2835-cpufreq: switching to governor ondemand
[   19.431082] bcm2835-cpufreq: switching to governor ondemand
[   21.736829] Adding 102396k swap on /var/swap.  Priority:-1 extents:1 across:102396k SS
[   22.134893] ip_tables: (C) 2000-2006 Netfilter Core Team
[   22.174573] nf_conntrack version 0.5.0 (7774 buckets, 31096 max)
[  750.951153] smsc95xx 1-1.1:1.0: eth0: kevent 2 may have been dropped
Not crashed yet, probably stable.

Ya gotta love that last message, nicely semi re-assuring ;)

I did fit a set of cooling fins from Watterott (some nice IR heat pictures there):

As checked with vcgencmd measure_temp, the temperature never rose above 58.4°C.

Onwards!