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32MB RAM Upgrade for WRT54GL?

Discussion in 'Tomato Firmware' started by philstuf, Jul 19, 2007.

  1. philstuf

    philstuf LI Guru Member

    Hi all.

    I have looked through the forums and was unable to find anyone else who attempted this (or their end results): I am going to replace the 16MB RAM chip on my WRT54GL v1.1 (running Tomato 1.07) with a 32MB chip. Has anyone else out there done this? If so, did you hit any stumbling blocks?

    I guess one could ask why I would do this, but I've always been one of those people who likes to tinker (That, and I keep making larger and larger ad server/hosts files). I found that an individual had already successfully done it, but with OpenWrt instead of Tomato (link). I'm curious to see how Tomato reacts, and hoping a recompile is not needed.

    I guess I'm just not content to leave well wnough alone, but I'd bet that's why most of us bought one of these in the first place...
  2. roadkill

    roadkill Super Moderator Staff Member Member

    I've been thinking about it for a while now.. please post your progress
  3. philstuf

    philstuf LI Guru Member

    Progress: So far, I've orderd the parts from Digi-Key, for a bank-shattering $7.56 per chip (Only one chip needed). I expect I'll have them by the middle of next week, depending on how quick they go out the door.

    The chip I ordered is a Micron 32MB DDR SDRAM chip, manufacturer part number MT46V16M16TG-6T IT:F TR. The Digi-Key part number is 557-1018-1-ND.

    When they come in, I'll break out my camera. Hopefully, I will not be posting pics of smoked hardware.
  4. Zoltair

    Zoltair LI Guru Member

    I will certainly be interested in your progress....!! : )
  5. mstombs

    mstombs Network Guru Member

    Double the size of the flash as well and you will have a WRT54GS v1.1 !
  6. roadkill

    roadkill Super Moderator Staff Member Member

    btw what equipment are you using?
  7. philstuf

    philstuf LI Guru Member

    For the router, it is just a plain (for now) Linksys WRT54GL v1.1 running Tomato 1.07. Got it after a very convincing demo of Tomato by a friend of mine.

    If you're asking about the soldering equipment, I will be borrowing an Edsyn 951SX adjustable temp solder station and a hot air "device" cobbled from a heatgun and a narrow-tip nozzle. Also generic solder wick, silver solder, and a "sold-a-pult." Oh yeah, and flux. Lots of flux.

    Hope that helps.
  8. Bonez116

    Bonez116 LI Guru Member

    uh nice i found only a 256MB with this part no. manufacturer part number MT46V16M16TG-6T IT:F TR. The Digi-Key part number is 557-1018-1-ND.
  9. philstuf

    philstuf LI Guru Member

    That's 256 Megabits, which equals 32 Megabytes. The original piece is 128 Megabits, or 16 Megabytes (just divide by 8 to get the bytes from bits).

    Here's Micron's PDF on the chip: Link.

    Mb normally represents megabits, while MB should be megabytes. Digi-Key doesn't help matters when they do their SKU description in all caps.
  10. Bonez116

    Bonez116 LI Guru Member

  11. philstuf

    philstuf LI Guru Member

    That's the site I got the part number from as well. Same one as in my first post, but I didn't make the link very prominent, sorry.

    He was running OpenWrt, and mentioned that he may need to make changes for the kernel to pick up the extra 16MB and use it. He didn't have to make changes to the kernel, but since I am running Tomato, I was curious if the software side had to be changed to use the extra RAM.
  12. philstuf

    philstuf LI Guru Member

    "I bent my Wookie..."

    Well, It is with great shame I return to the forum to update. :sad:

    I would like to wish my WRT54GL the best in the afterlife, as I got a bit overzealous with my removal of the old RAM chip and lifted several solder pads without knowing it. This'll teach me to not pay attention to my temperature.

    Despite the lifted pads, I decided to continue, repairing them as best I could. First power on after the fact gave me a blinking power light and 4 solid LAN lights. Did some more checking and resoldering, and I wound up with a booting router. When it came up, perhaps in a bit of irony (or a fit of vengeance), it showed 8MB of RAM. :wall:

    Despite booting and allowing me access via the web interface and SSH, it never let me back out to the interwebs, and I had to put my old router in place (BEFSR41)

    It looks like I know what I'm gonna do with my $50.00 Newegg gift certificate now... Maybe I'll play with the new one I order, but with a bit more caution, as I still have 3 chips left...

    (Insert various expletives here)


    Update: I fixed it!
  13. mraneri

    mraneri LI Guru Member

    Hey, if you didn't try it, it would have been eating you up inside for a long time. soldering that stuff really is a pain in the Axx. I'm in the IC industry, and we have techs that can handle 0201 size components in 4x4mm multichip modules... Sick stuff. Removing those 60+ pin devices from a board is a different kind of art in itself. Tough stuff.

    Anyway, how big a hosts file do you have on your router? I'm using MVPS's list, downloaded weekly, and it only takes a little more than 1MB of extra RAM. You must have some nasty huge hosts file. When I'm all booted, I have >50% of the RAM available.

    Anyway, good luck with your next router!
  14. dvaskelis

    dvaskelis Network Guru Member

    One of the things I've always been curious about Tomato is how it handles memory. My primary gateway wireless router is a Linksys WRT54GS v2 running Tomato 1.07, screen shot attached of free memory as it has 32MB of RAM from the factory. It pretty much hovers at close to 50% available RAM as well.

    Attached Files:

  15. mraneri

    mraneri LI Guru Member

    Depends on

    Administration -> Debugging -> Count cache memory as free memory...

    I keep it checked. So 50% of my RAM is cache OR free.. With 32MB, I suspect 50% in your case is FREE. (i.e. Cache counts...) Check the above setting. I bet it is unchecked.
  16. dvaskelis

    dvaskelis Network Guru Member

    After checking "Count cache memory as free memory", the Status: Overview page now shows now says "Total / Free Memory 30.03 MB / 19.93 MB (66.37%)".
  17. philstuf

    philstuf LI Guru Member


    I fixed the bad traces after removing the chip (again), and found out the silkscreening had me fixing a trace one pin over... In short: It's fixed! :biggrin:

    Now, it is showing 30MB of system RAM, with 22MB free! Looks like I got the pins right this time.

    Old GUI stats:

    Old Top via SSH:


    New Top via SSH:

    Now that it works, It's time for a drink. Will upload pics of the board when I finish.

  18. philstuf

    philstuf LI Guru Member

    I'm using MVPS's list as well, just stripped all the comments (seems pretty thorough). I was leary at first about using a bigger file, as the router seemed to be peaking on RAM (This was prior to me showing cached RAM as free, but AFTER I ordered the RAM chips). Back when I was using a dedicated Linux PC for a firewall, I had a hosts file that was closer to 2 MB, so I was sort of planning for the future...

    Since I've only been using Tomato for a couple of weeks, I have only cleaned the comments out of the MVPS file, and added a few internal static hosts (network printers, VOIP adapter, some aliases, etc.).
  19. njeske

    njeske Network Guru Member

    this is a cool little trick to do. i suck with a soldering iron or i'd probably attempt it.

    if i wanted to use the MVPS host file, where in the router would i put it? startup script? do i need to add anything before or after for it to work?
  20. philstuf

    philstuf LI Guru Member

    mraneri has posted some great scripts here:

    Mine just about looks like his second one, but I am downloading my own tweaked hosts file posted on my personal web pages (You know, the ones the ISPs give you just for having an account :smile: ). Since I already tweaked/cleaned the file, I didn't need to have the grep portion in the script. I have my script in the WAN Up tab of Tomato's scripts page.

    I probably should change mine to be more like his first script, with a "test" and "if" statement so mine won't download the file every time the WAN interface cycles.
  21. philstuf

    philstuf LI Guru Member

    More pics

    More pics of my project...

    Oh Really?:

    The Victim (OE Hynix 16 MB chip):

    The screw up (Note the 5 lifted pads):

    The repair (Ugly, sorry):

    I was lucky enough to be able to tie the pins to the vias on the other side of the board and have it work...
  22. mraneri

    mraneri LI Guru Member

    Definitely lucky!!! Congrats!! Nice job. (THough not pretty!!! - but it works!!!)
  23. lwf-

    lwf- Network Guru Member

    I just got one question - why? I have the GL 1.1 with 32MB RAM, but more than half of it is free anyway so why bother?
  24. yaqui

    yaqui LI Guru Member

    Why not ? If it's cheap and fun to do, might as well.
  25. rcordorica

    rcordorica Network Guru Member

    thats what i first thought, but then realized that it would provide more space to host a small web server, or files, or even keep logging information.

    If anything, the upgrade would help with high connection volume routers that reach into the 10K connection limit.

    + Linux uses free RAM as a cache.
  26. M_ars

    M_ars LI Guru Member

    one thing is missing :)
    push the cpu to the limit. Mine is running fine @ 250MHz ... ;
  27. philstuf

    philstuf LI Guru Member

    I would normally agree with you there, but my v1.1 GL came with 16MB of RAM and only had a couple of MB free. Since I have a tendency to tinker with my embedded Linux projects (My Linksys NSLU2 is a NAS only as a secondary function), I figured it was worth the $7.65 the chip cost me to have the extra breathing room. Plus, I wanted to see if I could do it (almost smoked it though).

    Besides, I doubt any of us here who are using third party firmware are content to leave something "as-is." That's why the GL even exists in the first place: The enthusiasm the users have for their sandbox.
  28. lwf-

    lwf- Network Guru Member

    Sorry, I meant GS v1.1, GL only has 16MB.

    OK, I can understand that some of you could risk your router for the fun of it, but I would not risk my old GS even if I got a 64MB chip for free, I dont even know what to do with my unused 16MB. ;)

    By the way M_ars, does your overclocking do any actual difference that you can show?
  29. Quijy

    Quijy LI Guru Member

    I have been following this chain, GLAD TO SEE IT IS WORKING. I have 5 GLs and may need a few more shortly. I have been reading on this mod on other sites and noticed on one a change of a pin swap needed to make this work. My question, is the Micron a direct pin to pin swap?
  30. philstuf

    philstuf LI Guru Member

    Thanks, I am glad it is working too. I really thought I was going to have to trash it...

    The chip I used is a direct pip to pin swap. The only reason those wires are there is due to mistakes made during the desoldering process. They replicate circuit paths that existed prior to my attack on the router.

    Aside from repairing the solder pads/traces I damaged, I made no other changes to the unit.

    Part Info
    Micron part number: MT46V16M16TG-6T IT:F
    Digi-Key part number: 557-1018-1-ND
    Package: 66 Pin TSOP
  31. roadkill

    roadkill Super Moderator Staff Member Member

    now, would 128MB upgrade is possible?
  32. Quijy

    Quijy LI Guru Member

    thanks, I think 32mb will be much better than 16mb as another poster just asked can we do 128mb. My guess is no. I am sure there is a limit to what the little processer can address. With the SD mods that should give you 1gb of memory to do most anthing. Then again, I do not know the full limits if this box yet.
  33. philstuf

    philstuf LI Guru Member

    Found some info on a guy who upgraded to 64MB of RAM:

    If I had read that first, I might have popped for the larger chip. Guess I'll have to try that on my next GL :).

    I also read that the Broadcom processor (BCM95352E) should support up to 256MB of RAM... It would be nice to be able to pop in a few chips and try (without having to solder them each time). I wonder if I can find a 66 pin TSOP socket. :hmm:
  34. Quijy

    Quijy LI Guru Member

    I found 32mb and 512mb chips, but no 256mb, 128mb or 64mb chips. still looking, I checked Mouser, State Electronics, and Digi-Key. What is interesting the 512mb chip looks to be the the same bus as 256mb. Wonder if it would work? Digi-key has the 512mb for $13.00. may be worth a try.
  35. yaqui

    yaqui LI Guru Member

  36. yaqui

    yaqui LI Guru Member

  37. roadkill

    roadkill Super Moderator Staff Member Member

    TSOP socket sounds like a good idea...
  38. mstombs

    mstombs Network Guru Member

  39. yaqui

    yaqui LI Guru Member

  40. RobNC

    RobNC Network Guru Member

    DDR supported - by Buffalo WHR-HP-G54?

    Any of you all with a voltmeter - can you measure the voltage between VSS and VDD? My Buffalo WHR-HP-G54 shows 3.3V, which means I can't use DDR (requires 2.5V I/O).

    VSS would be pin 66, and VDD pin 33.

    Looking at the chip, with the "notch" at the top, pin 33 is the last (lowest) pin on the left and pin 66 is the highest pin on the right.
  41. philstuf

    philstuf LI Guru Member

    I'm thinking about getting that, just to see if it will work. The diagram doesn't reveal as much as I'd like, but it's only $7. I think I'll order it and try it on another 54GL, though, as I don't think mine will handle any more soldering/desoldering to the chip.
  42. philstuf

    philstuf LI Guru Member

    I'll check as soon as I get home, but a quick review of the spec sheet for the Micron chip I used shows VDD and VDDQ to be 2.5v min, 2.7v max. I'm inclined to think this chip will not work with your router. Do you have the part numbers off your chip? It may be possible to spec out a larger capacity chip that works for your router that way.
  43. philstuf

    philstuf LI Guru Member

    Just checked (sorry about not doing it sooner), and the voltage across pin 66 and pin 33 is 2.51 Volts.
  44. JPorter

    JPorter LI Guru Member

  45. s0dhi

    s0dhi LI Guru Member

    Just completed the WRT54GL v1.1 upgrade to 64mb.

    Had a professional (my mom) take care of the SMT chip swap, she normally works on aerospace, aviation, and military electronics.


    Now, what should I do with all that extra RAM?

  46. Kiwi8

    Kiwi8 LI Guru Member

    Maybe u can create some as swap space, while the rest of the RAM is good in allowing u to have many connections far greater than 10000.
  47. lwf-

    lwf- Network Guru Member

    Download the Internet to it so that you can surf super fast. ;-)
  48. s0dhi

    s0dhi LI Guru Member

  49. basmic

    basmic LI Guru Member

    Did she use one of those solder guns, which blow hot air to melt the solder?

    How did you know which chip to use?

    Just curious, because I'm wondering if I can upgrade my WRT54GS v1.1 from 32mb to something more.
  50. s0dhi

    s0dhi LI Guru Member

    From what I understand, the area around the chip was masked, then a solder air gun and flux was used to remove the chip. Not sure what the total process was, but I was told it took under 15min end to end.

    There is a fair amount of information about RAM upgrades online. I used some resources at the OpenWRT wiki and forums.

    This upgrade seems to be device specific, so there is some research involved.
  51. jersully

    jersully LI Guru Member

    Go mom!!!!!
  52. guillaumy

    guillaumy LI Guru Member

    Impressive work!

    Personally though, I feel changing the flash chip of the later models (followed by the challenging task of Jtagging) is probably more useful

    Or ... dare I say bring it up again ... if someone could come up with a "micro" version of Tomato ...:wink:
  53. kameleon

    kameleon LI Guru Member

    Would your mom be open to doing a few of these for some of us? Of course we could pay. ;) I would love to upgrade one of my 54G v2.2 routers but do not have nearly steady enough of a hand to do that.
  54. s0dhi

    s0dhi LI Guru Member

    I would hold off on that for now. I just had the second one done and it appears to have bricked. I will see if I can bring it back to life via JTAG.
  55. alienrex

    alienrex Addicted to LI Member

  56. illusion

    illusion Addicted to LI Member

    Big problem

    hello! Im from Russian, in Russia but module memory (MT46V16M16TG-6T IT:F) its a problem=\ Please, submit or give me! will be very grateful!
  57. jsmiddleton4

    jsmiddleton4 Network Guru Member

    I certainly can understand tinkering, hobby mindset, with the best of them. But why not put in sockets? A socket for flash chip, socket for memory chip?

    In the interest of bang for the buck me I'd probably just buy a Linksys 54-tm model off ebay and be done with it.
  58. gawd0wns

    gawd0wns LI Guru Member

    Would there be any difference in speed/performance between a RAM module and a flash card in a socket? Granted, the socket option will allow more flexibility since you can use memory cards with high storage capacities.
  59. Toastman

    Toastman Super Moderator Staff Member Member

    Without looking to see what is available, the common source of memory chips is from SODIMM notebook memory sticks which generally won't fit in sockets. I agree with Jim, if the TM is available, it is the wise thing to purchase. If not, then consider increasing memory on a GL only if you have access to, and are experienced in, working with proper soldering equipment. The chances of a succesful transplant by a normal soldering iron and solder is very small.

    gd ... It isn't a simple matter of putting in a DIMM socket, if that is what you are thinking. Also, the chips in our routers cannot normally access much more than 32MB of memory. Some address lines are also missing in many cases. Some people are said to have managed 64MB, but 32MB is more common and requires no special effort.

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