I am not responsible if your devices send you back in time, explodes, implodes, bricks or flies into space from the use of any software I put up.


Saturday, January 24, 2015

TP-Link WDR4900v1 OpenWRT Technical Review

As you can see from my github I am adding support to a new Router.
The TP-Link WDR4900v1.
The reason why I am supporting it is because I got 1 recently.

As you know this is a relatively old Wireless N Dual Band Router compared with all the spanking new Wireless AC Router, I saw that it was on cheap sale, $90 SGD compared to the original retail price of $190 and so I purchased it.

That was not all the reason I purchase it. The main reason was it came with a esoteric Processor: the Freescale e500v2 P1014 SoC.

It is a POWER Architecture by Freescale, Clocking up to 800MHZ.
It is a relatively high power Router with SPE register modes but from the Kernel Source it cannot boot if you enable SPE or Hardfloat on the Kernel however you can enable it in the userland applications.
Probably a GCC thing.

As usual this is not your Stock Firmware review, it is a "OpenWRT firmware on it" review so if you are looking for nice numbers on stock firmware you should look at the millions of reviews posted somewhere else.

I took a look at the default buildroot in OpenWrt for this firmware, there are a number of optimizations that can be applied but is not.

So I added my patches and the github repo can be found here.

A number of significant patches I added that boosted performance are the
CFLAGS, TX and RX buffer on the gianfar driver, and the Assembler Optimizations for OpenSSL similar to what has been done for MIPS Architecture, I will only upload the binaries next month but if you are impatient you can build it yourself from my github repo.

So below are some of the findings of OpenWrt on WDR4900v1after using my Optimized Build which I will only upload next month with the rest of my releases.

NAT Performance LAN to WAN

It is roughly 550Mbps, only slightly higher than a optimized Overclock WDR4300@730MHZ.
So if we were to consider Throughput per MHZ it would be slightly less efficient than a MIPS74kc.

As for Wireless @ 2.4GHZ Close range it maxes out at > 150Mbps peak burst using WPA2-PSK AES Encryption.
This is a very good result, probably due to its superior AES computation capabilities

2.4GHZ is very often the lower bar performance due to the channel congestion so we can assume that 5GHZ will be slightly high in throughput compared to 2.4GHZ

Next findings are very interesting. Although it uses similar Wireless Radios compared to WDR4300 it is way way higher Power.

Compared to the WR1043ND which can do 24dbm at 2.4GHZ, this Router can do 25dbm! (WDR4300 does a maximum of 22dbm at 2.4GHZ) but remember the 2.4GHZ antenna is INTERNAL therefore you cannot compare it to the EXTERNAL antenna of the WR1043NDv1

Lastly its 5GHZ capabilities is also clearly superior compared to its weaker brother WDR4300.

It can do a flat 22dbm on ALL 5GHZ Frequency compared to WDR4300 which can only do maximum of 20dbm on higher frequency range on 5GHZ and 15dbm on the lower frequency range on 5GHZ.

In conclusion, basically it is slightly faster than WDR4300 and can transmit higher power than WDR4300 and WR1043NDv1.

Stay tune for the Feburary Release!

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