Quote:About memory hardware modding:
Stock SB5100 modem has 8Mbyte SDRAM (1 M x 16bit x 4banks). When you power on modem, firmware that is stored in 2Mbyte flash memory chip in compressed form is being decompressed to the RAM and runs from there. Stock NOSH/GA firmwares take about 3,6Mb, and SB5100MoD about 4,6Mb of RAM. The rest of the RAM is used as memory for RTOS VxWorks data and IP packet buffers. If you run many torrent threads or your cable node is very saturated with users(and IP packets), modem can just reboot time after time (not enough memory scenaro). To make it stable and little faster you can try to add more RAM to have more room for IP packets. You can change 8Mb chip to 16Mb or even 32Mb. But you should know that RTOS VxWorks of SB5100MoD supports only 16Mb of RAM. If you install 32Mb, only 16Mb of it will be used. It's important to use only 16bit 4banks chips. 4, 8, 32 bits and not 4 banking will not do! Chips can be PC100 or PC133 as well (for example my SB5100i comes with K4S161632F-TC60 chip which is PC166).

Tested chips are: Samsung 16MB - K4S281632C-TL75 (2M x 16Bit x 4 Banks) and 32MB - K4S561632C-TL75 (4M x 16Bit x 4 Banks). Here is the reference for Samsung chips: http://www.samsung.com/global/business/semiconductor/products/dram/downloads/SDRAM_code.pdf
Alternatively you can use Micron 16Mb - MT48LC8M16A2 or 32Mb - MT48LC16M16A2. Or any 2Mbit(4Mbit) x 16bit x 4banks of any manufacturer. Just read specifications.
Motorola used MT48LC4M16A2-75 on my SB5101i.

Remember: 80ns is PC100, 75ns is PC133, 60ns is PC166. The less the number on the end of the chip the better.

To test RAM for errors after memory upgrade, go to telnet and enter:

cd c
test_bcmalloc



To see memory status go to the SB5100MoD WebGUI->Tools and press memShow button. Or enter memShow in telnet.

Note: If you do not run heavy torrents or do not have issues with rebooting, consider not to memory mod your SB5100 because it's dangerous operation. If you want to do it, just be careful when soldering. Use good soldering technique like shown here http://www.tcniso.net/Nav/Video/tcn_video2_tsop48.wmv but is advised to use an special SMD rework station. By using simple techniques you can seriously run the risk of damaging the glue that holds the traces to the PCB!

(23-11-2009, 02:05 AM)donkey01 Wrote: Any Specific Brand/Model number of chip that works the best? I've tried 3 differnt Nanya NT5SV16M16AT chips (32Meg 16 bit by 4 bank out of an old laptop) and Could not get them to work(modem would not finish booting) I've already put back the stock memory chip and works just fine, so I know it's not the modem. I have a hot air rework station and am capable of replacing the chip just fine. Not sure if I just had a bad/wrong chip. Anybody have any favorite confirmed working brand/model of chip other than the one's previously mentioned in this thread?

(24-11-2009, 03:53 PM)rajkosto Wrote:

(23-11-2009, 02:05 AM)donkey01 Wrote: Any Specific Brand/Model number of chip that works the best? I've tried 3 differnt Nanya NT5SV16M16AT chips (32Meg 16 bit by 4 bank out of an old laptop) and Could not get them to work(modem would not finish booting) I've already put back the stock memory chip and works just fine, so I know it's not the modem. I have a hot air rework station and am capable of replacing the chip just fine. Not sure if I just had a bad/wrong chip. Anybody have any favorite confirmed working brand/model of chip other than the one's previously mentioned in this thread?

32Mbit/8=4MB
no wonder it wouldn't boot.