What is the difference between SDK5.X+ and non-versions?

[calculon]

First off, hey RMerlin, I know you don't recognize this username, but wanted to say thanks for the help when this router initially came out. You gave us some good ideas for dd-wrt and other things.

Anyways, I have moved from dd-wrt back to asus-wrt for
1) Speed
2) Stable(r) Wireless
3) USB/IPset
4) Just to be back on stock-(ish)

First off, I wanted to make sure that it is okay to just go straight from asus-wrt to asuswrt-merlin without deleting any configuration from nvram. If I have to, I can, just sorta a pita to set everything back up.

Second, What is the difference between SDK5.X+ and the non versions? If I have done the 64K NVRAM mod, and am coming from stock asuswrt, what can I flash?

Third, asuswrt-merlin is based off of ASUS RT-N66U Firmware Version 3.0.0.4.374.720, right? Or is it based off an older source? I saw a thread about it not being on the newest one (the firmware released in October).

Fourth, what are the changes in the beta versus stable? Do you have a changelog?

Thanks

 

[CooCooCaChoo]

1. Maybe. But always a good idea to wipe out problems before they start.

2. There are two firmware types: SDK5 and SDK6. Depending on which router you have, one or the other will be better for it and they primarily have to do with the wireless driver being used in the kernel.

3 & 4: Changelogs! http://www.lostrealm.ca/asuswrt-merlin/changelog.txt

 

[calculon]

I am using a ASUS RT-N66U Router, which is why I am curious. There is only one file that has an SDK 5+ firmware, the rest don't mention it.

 

[L&LD]

If you're talking about the -36Beta1 SDK5 version of the N66U firmware; that is the one I'd recommend at this time.

http://www.mediafire.com/download/ups085eda5s82d1/RT-N66U_3.0.0.4_374.36_beta1-sdk5.zip

 

[RMerlin]

The RT-N66U was initially designed running SDK5 (that means wireless driver version 5.xxx). The RT-AC66U was based on a newer Broadcom SDK (due to the addition of 802.11ac support for instance), and is using a driver version 6.30.xxx.

When Broadcom updated the driver from 5.100 to 5.110, they broke compatibility with a number of wireless devices. Intel devices for instance were unable to connect. When Broadcom and/or Asus tried to fix it and failed, Asus gave up and updated the RT-N66U to use the same driver (6.30) as the RT-AC66U. While this fixed all connectivity issues introduced in 5.110, it caused the RT-N66U to lose a fair amount of signal strength (nearly 10 dBm if I recall correctly), possibly because the router wasn't originally designed/tuned for that SDK.

It took a fair amount of work (it's not just one file that needs to be replaced but various kernel patches as well), but I managed to re-apply driver 5.100 on top of the latest firmware code. That is the so-called "SDK5 build". It lacks some of the HW acceleration improvements of the 6.30 code, might possibly not be as stable (since it's pretty much Frankenbuild), but it resolves the signal strength issue.

Most users will prefer to run the SDK5 build instead of SDK6 build, as so far it has proved to still be as stable as the regular build despite all the "code splicing" it required.

As for whether you need to revert back to factory default, in the case of the RT-N66U, this is needed if:

1) Coming from a much older version
2) Switching between different SDK (Asus's stock 374 is SDK6)

Concerning changes, they are always documented in the linked changelog.

 

[RMerlin]

Third, asuswrt-merlin is based off of ASUS RT-N66U Firmware Version 3.0.0.4.374.720, right? Or is it based off an older source? I saw a thread about it not being on the newest one (the firmware released in October).

Whoever wrote that didn't know what he was talking about. The current code is based on code that's much newer than 374.720. It's close to the 374.1631 beta that's been floating around lately, minus the wireless driver that's from the 374.979 build.

The revision number ordering just don't match because Asus has a separate build tree for the MIPS and the ARM routers. 374.501 (ARM branch) is two months newer than 374.979 (MIPS branch) for instance.

 

[korrakas]

The RT-N66U was initially designed running SDK5 (that means wireless driver version 5.xxx). The RT-AC66U was based on a newer Broadcom SDK (due to the addition of 802.11ac support for instance), and is using a driver version 6.30.xxx.

When Broadcom updated the driver from 5.100 to 5.110, they broke compatibility with a number of wireless devices. Intel devices for instance were unable to connect. When Broadcom and/or Asus tried to fix it and failed, Asus gave up and updated the RT-N66U to use the same driver (6.30) as the RT-AC66U. While this fixed all connectivity issues introduced in 5.110, it caused the RT-N66U to lose a fair amount of signal strength (nearly 10 dBm if I recall correctly), possibly because the router wasn't originally designed/tuned for that SDK.

It took a fair amount of work (it's not just one file that needs to be replaced but various kernel patches as well), but I managed to re-apply driver 5.100 on top of the latest firmware code. That is the so-called "SDK5 build". It lacks some of the HW acceleration improvements of the 6.30 code, might possibly not be as stable (since it's pretty much Frankenbuild), but it resolves the signal strength issue.

Most users will prefer to run the SDK5 build instead of SDK6 build, as so far it has proved to still be as stable as the regular build despite all the "code splicing" it required.

As for whether you need to revert back to factory default, in the case of the RT-N66U, this is needed if:

1) Coming from a much older version
2) Switching between different SDK (Asus's stock 374 is SDK6)

Concerning changes, they are always documented in the linked changelog.

Sorry for the necro but does this statment still apply ? Or have your newer SDK6 builds also resolved the signal strength issue ?

 

[RMerlin]

The wifi performance notes still apply, however I do not recommend running the SDK5 builds because they are getting quite old, and are missing on numerous bug and security fixes.