My motherboard uses nVidia's nForce 570 SLI chipset. It has 2 ethernet ports. I've installed RedHat EL4 update 7 (kernel 2.6.9-78.0.13) and used "up2date" to get the latest package updates. With only 8GB RAM, the ethernet ports function properly. If I add another 8GB RAM, total of 16GB, the ethernet ports no longer function properly. They won't initialize.

Does anyone have any ideas?

I'd start with google to see if you can find any similar problems. Then, I'd look in the driver source code for the driver writer and send him/her an email to see if the problem has been encountered before. You might also consider joining the network driver mailing list for a short while to ask questions, there. I've generally found the driver developers a good bunch to talk to, but a word to the wise: don't start off a driver mailing list post with "this driver is broken, can someone fix it?" Also, they are pretty busy.

Another good place to start is to search the developer archives here:
http://kerneltrap.org/mailarchive/linux-netdev

I've spent a lot of time searching the web trying to find help. Perhaps I'm not using the correct words/phrases for the search, but I can't find anything that helps. I've installed RedHat5 update 3 and seen the same behavior as RH4.7. I installed the latest driver as found on nVidia's website on RH5.3 and still the problem persists. I've sent emails to the author(s) of forcedeth for help. I have customer service at RedHat working on the problem. Not sure what else to try.

-Keith

I wish I had something better to offer you. I spent maybe 30 minutes looking around and found nothing.

So, if I were in your shape, and could come up with a spare drive, and the downtime, I'd load up Debian Lenny (only because that's what I know best, you might just clone your system and try later kernels) and see if the problem still existed. If not, I'd work my way backwards in big jumps to see if there was any particular kernel that fixed it.

The only other thing I have to offer is a question: are you really using up 8GB of RAM and need more?

I'm limited in options. Here's my dilemma. I'm a hardware engineer designing computer chips (ASICs, FPGAs, etc) and boards. Altera, a corporation that manufactures FPGAs, produces EDA software called Quartus which is used to design the FPGAs. When running Quartus to target their largest StartixIV FPGA, Quartus can consume as much as 8GB of RAM. It isn't unusual for me to work on multiple chips at the same time, so I'd very much like to have the ability to run 2 copies of Quartus which means I could be consuming 16GB of RAM between the 2. For Linux, Altera has qualified Quartus to run on only RedHat and Suse. I have the choice of RedHat 3, 4, and 5 with RedHat 3 no longer being supported for the latest release of Quartus. I could try older versions of RedHat 4 or switch to Suse.

Maybe RedHat support will help. If not, hopefully the forcedeth driver authors can help me. Thus far, the author has mentioned that maybe the problem is address mapping in the driver. I've supplied some information to them for debug. If that's true, and not able to be fixed in a timely fashion, I've considered one other option which is to install another NIC in the system. Perhaps a different NIC would have a driver that works for a 64-bit system with more than 8GB RAM.

-Keith

Good point about just getting another NIC. Sometimes we can get so consumed about solving the problem that we forget to just step around it. Good luck!

I installed Fedora 10. System works great with all 16GB RAM. Not sure how different Fedora 10 is compared to RedHat 5.3, but I do know the kernels are different. Fedora 10 uses 2.6.27 whereas RH5.3 uses 2.6.18. Too bad I can't stay with Fedora; the EDA applications aren't qualified on it.

-Keith

I installed an SMC NIC model 1211TX (had one lying around). The NIC has RealTek RTL-8139 chip on it. RH5.3 uses 8139too module for the driver. I still haven't been able to get the forcedeth driver to work for RH5.3, but the system works great with the SMC NIC with all 16GB RAM. Good enough for now.

-Keith

Just to be complete about this thread...

I had to disable the built-in network ports on the motherboard that use the forcedeth driver. With them enabled, RedHat assigns devices eth0 and eth1 to those ports and eth2 to the SMC NIC. Since the FlexLM licensing tools read device eth0 to get the MAC/HostID for the system, the license server wouldn't start due to the failure to read eth0's MAC address. With the built-in network ports disabled, and some edits to /etc/modprobe.conf and all of the various ifcfg-eth* network startup scripts, I was able to get the SMC NIC assigned as device eth0 and to get the license server started.

-Keith

Hi Keith,

can you tell me which mainboard you are using? We are currently thinking about plugging 16GB into an Asus M2N-SLI deluxe, also based on the nforce 570 SLI. The manual says that it only supports 8GB... Is that because the manual is dated 2006?

Jochen

My mainboard is from Biostar model TF570 SLI. The manual that shipped with the board claimed to support a maximum of 4GB RAM. The on-line manual at Biostar's website was updated to support a maximum of 8GB RAM. Through a bit of email back-and-forth with Biostar's technical support, I learned that the maximum supported RAM is based only on what Biostar had physically tested; they hadn't tested anything more than 8GB RAM.

I have been using 16GB RAM in my system for many months now with no issues (after solving the ethernet port problem...unrelated to the actual RAM). I've run well over 24 hours of memory test using memtest86+ with no errors. The RAM is from Patriot and is two sets of 2 x 4GB (i.e. 2 sets of matched pairs).

-Keith

Hi Keith,

thank you for the info. I previously searched the forum at Asus but without success. Guess that I will write an eMail too...

Did you find anything new about the ethernet problem or are you still using the additional NIC? BTW, using Debian there is a tool named "ifrename" which does the trick to rename devices e.g. based on their MAC address. Don't know if this is also available at Red Hat or Fedora...

Jochen

Because the memory controller is built into the AMD processors, I wouldn't be surprised if your ASUS board supports more than 8GB RAM as well. As long as ASUS routed all of the memory address traces on the board and there are no signal integrity issues for the traces, you'll probably be fine.

I am still using the "extra" NIC. RedHat 5.3 just doesn't work correctly with the built in ethernet ports. I suspect the next release of RedHat will work correctly since Fedora works correctly.

-Keith