The reason why I started this thread is to combine all information regarding overclocking from the OpenWrt Forums as well as other sources.
This is a running thread so hopefully any new information can be added as part of discussion.
- To squeeze more performance out of your device if your ISP subscription is 200Mbps and currently your router is hitting 180Mbps perharps you can reach 200Mbps with a little overclocking
- Overclocking improves Wireless performance since WPA2-AES encryption is de-facto standard, computing power is required
- Because you can, people have been overclocking ever since the old Intel Celeron Era, it is fun
Manufacturers do not test each chip individually so maximum stable clock difers from chip to chip as well from board revision to board revision.
You want to increase the clock rate and keep the stability.
General strategy for Overclocking
- Increase by Minimum Stepping (Depending on SoC Architecture) Eg. +10MHZ
- do memtester, do iperf test over LAN/WAN, do iperf test over WiFi
- test using heavy bittorrent workloads
- If it does not crash/reboot suddenly you can repeat step 1
- If it crash, reverse the last working value and that is the safe limit
AR71xx MIPS Overclocking
AR71xx MIPS is very overclocking friendly, clockspeed is determined by a register value initialised in the uboot
There are 3 Clock Parameters
There are currently 2 types of AR71xx MIPS:
The old eg. AR7240, AR7100, AR9132, AR7242, AR7241
For these Routers all 3 Parameters are tied together meaning
eg: CPU = 400MHZ, DDR = CPU = 400MHZ, AHB = DDR/2 = 200MHZ
The new eg, AR9344, AR9341
For these Routers all 3 Parameters are NOT tied together meaning
eg: CPU = 535MHZ, DDR = 400MHZ, AHB = DDR/2 = 200MHZ
General strategy for AR71xx MIPS Routers
- Backup your uboot
- Open the uboot using a HEX Editor
- Search for unique hex value string loading the clockspeed value in the uboot
- Replace the string by incrementing the value and save to another copy
- Overwrite the uboot with the modified copy