Will a Ethernet PCI card cut down CPU Usage?

[Mithan]

Just curious if a Ethernet PCI card would cut down CPU Usage over an Ethernet port built right into the motherboard?

 

[imported_fx]

No..

 

[ForumMaster]

yup. just like a pci sound card. u'll need to disable the built in ethernet in the BIOS and it should help. but it won't reduce hdd usage.

 

[SLCentral]

Yes, but it will be very insignificant.

 

[Cerb]

It depends on which it is. Recent Intel NICs use very little CPU. Overall, I think it will be insignificant, though.

 

[Lord Evermore]

Cheap PCI NICs use the exact same LAN controller that onboard networking uses, or worse. (For example SiS chipsets use SiS900 LAN controller, or you can buy PCI cards with the same controller.) Current chipset-based networking really doesn't use significant amounts of CPU power. In order to see dramatic differences, you have to get high-end PCI network cards, which are expensive, and therefore generally not really worth your while. Unless you're flooding 100Mbps of data continuously over the LAN while also running CPU-intensive applications where a few extra percent is going to make a difference, don't bother.

 

[Brian48]

I'd stick with the on-board, but here's an interesting article for you (benchmarks included).

Network Card Roundup - Which is the Best PCI Network Card?

 

[Tostada]

I've got an older $50 3COM ethernet card that has a couple good-sized chips on it that say "Parallel Tasking III" or something like that, and I think it was supposed to take all the load off the CPU. All the other 10/100 PCI cards I have are little $10 ones that have really tiny boards. I always figured it was about the same as a WinModem. The cheap ones have to use the driver to do all the work in software, but it's probably not that big a deal.

I have two machines connected over their on-board NVidia GBLAN ports, and when I transfer files at gigabit speeds between them, my combined CPU usage actually does jump around between 8% and 10%. That's on an Athlon X2 at 2.5 GHz. It looks like all the usage is coming from System and explorer.exe ... mostly from explorer.exe being at 6% CPU usage. So I'm not sure what that means.

Anyway, the load can be significant with gigabit ethernet. Not really with 100 mbit ethernet.

For example, most network cards aren't any more complicated than your built-in ethernet and therefore won't offload any work, but look at this card:
http://www.newegg.com/Product/Product.asp?Item=N82E16833106202

It's much more substantial than most cards, and specifically lists features:
TCP Checksum Offload
TCP Segmentation/Large Send Off-load

 

[Lord Evermore]

Don't forget, when you're transferring files, you also have CPU usage due to the hard drive having to read/store the data, so that accounts for some of the CPU usage. And full Gigabit data transfer is a pretty huge amount of data per second, more than any single drive can read or write continuously.

CPU speed has increased so much that the difference in usage with cards which offload some of the work to the CPU compared to ones that do more work on the NIC is negligible. Pretty much the same as has happened with all hardware vs. software comparisons.

 

[Mik3y]

Onboard's perfectly fine. You won't be able to notice the drop in CPU usage if you even get a good ethernet controller card.

 

[Tostada]

Originally posted by: Lord Evermore
Don't forget, when you're transferring files, you also have CPU usage due to the hard drive having to read/store the data, so that accounts for some of the CPU usage. And full Gigabit data transfer is a pretty huge amount of data per second, more than any single drive can read or write continuously.

CPU speed has increased so much that the difference in usage with cards which offload some of the work to the CPU compared to ones that do more work on the NIC is negligible. Pretty much the same as has happened with all hardware vs. software comparisons.

You're wrong when it comes to Gigabit Ethernet.

First, you're not hard-drive limited. Gigabit over copper isn't that fast. It seems to peak closer to 150mbit actual throughput. Also, CPU utilization varies quite a bit. Check out this review. It shows the performance of both the NForce4 Gigabit LAN and the Marvell Gigabit LAN on a DFI board, and it also shows that it can take the CPU utilization up to 19% on an Athlon 64 FX-53.

http://www.barrys-rigs-n-reviews.com/re.../2005/hardware/smc8508t/smc8508t_2.htm

I didn't even realize the LAN drivers defaulted to having Jumbo Frames turned off, and setting "Optimize for Throughput" in the driver also helps significantly.