high CPU usage on gigabit ethernet

[Freeco]

I bought my Synology DS-209+ this weekend, so I quickly transfered most of my data onto the NAS over a wired gigabit connection.
While I was monitoring the speed (about 33-34MB/s) I noticed the CPU usage of the client PC was quite high: 70-80%, while my AVG was disabled.
As it's a Core2Duo 2.4GHz machine (4GB of RAM, running Vista x64 ultimate) I think with my limited network knowledge this is caused by the old D-link DGE-530 NIC I've installed.

Could I improve this? Eg by purchasing a newer gigabit NIC with a PCI-express interface. I'm thinking of an Intel PRO/1000 PT or GT card. (any difference aside from the PCI/PCI-express interface?)
Or is this CPU load just normal?

 

[00Roush]

I tried searching online to find out if that card has any tcp offload features and it looks like it does not. So if you were to use a card like the Intel Pro 1000 GT that does do tcp checksum offload it could defiantly lower your cpu usage even staying on the PCI bus. But if you are deciding between the PT and the GT defiantly get the PT. The two cards are similar in features but the PT allows you much more room to grow. One less bottleneck to worry about in the future.

For reference...
My cpu usage is around 40-50% for writes and 45-60% for reads from/to my client. Transfer speeds as reported by Vista are usually between 90-100 MB/sec. Client uses a Athlon 64 X2 5400+ cpu with 4GB RAM on Vista x64 Ultimate. Network card is intergrated on the motherboard and is based on the Marvell Yukon 88E8056 PCI-e gigabit ethernet controller. Server is a DIY home build. Opteron 165, 1GB RAM, Win XP Pro SP2 and another onboard Marvell ethernet controller.

In general I would say that your cpu usage seems a bit too high considering the transfer speeds you were seeing. Before you purchase a new card though I would consider checking for driver updates from D-link.

00Roush

 

[Madwand]

Check the NIC's advanced properties, and ensure that interrupt moderation is enabled, as are offload options, and enable jumbo frames if it's supported by your switch and NAS (and enabled there). I believe it's a Marvell-based NIC. You can also try downloading and installing the latest drivers from Marvell.

An Intel PCIe NIC would be "better", but the one you have should be OK, and the utilization should not be that high on that CPU.