Hi all, Finally, I SOLVED my issues. There was a strange problem with my Cisco SGS200 switch. For some strange reason, a single-NIC ATTO benchmark was fine, but multiple load on the switch resulted in very strange and sporadic slowdowns. Meanwhile, the intel I350 NIC works well in a 3-path MPIO sett...

Dear Volker, Thank you for your reply. I am sorry that I didn't point it out clearly again, our setup was described in more detail in post #1. There is no VMWare in our setup, but only a Windows Storage Server 2012 (iSCSI Target/StarWind), and a Windows Server 2008R2 client (iSCSI Initiator). I did ...

Finally, I managed to install the new intel NIC into the server machine. Connections using a single port are 10-15 % faster compared to the realtek NIC. However, unfortunately, changing the NICs or some side-effect has lead to some more serious problem: While a ATTO benchmark shows full NIC load in ...

Thanks. I ordered an intel i350t2 nic, and will come back later this week...

Thank you, jeddyatcc. My benchmarks with a localhost iSCSI connection on the server machine were great. 85-90 % of a local SATA connection (see previous post). So, I am not sure if this is a general iSCSI issue. One of your questions was, if the problem matters. In short: I think yes. We are using i...

Thank you all for coming back to me about this... I applied the recommended TCP/IP settings according to the pinned post. I applied the TcpAckFrequency registry patch. Also, I already played with the offload stuff. I went back to the previous release of the realtek drivers. Note: After all those cha...

Anyway, in my opinion, two issues remain strange:

- if it was due to slow NIC, MPIO should still scale somehow, but it does only for large blocks
- also for 64k atto results (comparing same queue depth, see post #1), StarWind is far away from physical performance

Matthias

Thanks. I will come back after I installed some other NIC...

Regards

Max, Thank you for coming back. I disabled MPIO, and did some benchmarks with just one NIC (see attached). Small transfer sizes remain very slow. As I stated earlier, I tried a different client (my workstation) with no MPIO, and low performance on small sizes. I used ntttcp to check the link, 890 MB...

Hi Max,

Thank you for your reply.

Yes, I have provisioned 512 MB write-back cache in StarWind.
Yes, I get the same results with jumbo frames turned off. To be clear: I used a cross-over lan cable to bypass the cisco swith, and disabled jumbo on both NICs - no performance increase.

Hi,
I am not so familiar with iometer, here are some results.

Hope this helps.

Best regards
Matthias

Maybe time to add some further network infos: - Server: 3 Realtek 8168 NICs using the latest driver (8.012, 2013/3/26), Jumbo enabled. - Switch: Cisco SGS2000 48-port, Jumbo enabled. No teaming or vlans etc. - Client: I meanwhile used my workstation computer to substitute the w2k8r2 client. My Win7 ...

Hi Max Thank you for your reply and for this extraordinary responsiveness! Please find attached some screenshots of the iscsi initiator. Please note: Although currently configured as "least queue depth", we tried "round robin" also. It showed a bit lower performance results compa...

Dear Support Forum, I have a simple setup to evaluate the iSCSI SAN, and I cannot manage to get appropriate performance results. Hardware: - iSCSI client: HP DL165, W2k8R2, using 3 dedicated NICs via MPIO . NICs have 192.168.0.1, 192.168.1.1, 193.168.2.1, only TCP/IP protocol active, MS initiator - ...