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10 Tips For Boosting Network Performance
snydeq writes "InfoWorld's Paul Venezia and Matt Prigge provide hands-on insights for increasing the efficiency of your organization's network. From losing the leased lines, to building a monster IT test lab on the cheap, to knowing how best to accelerate backups, each tip targets a typical, often overlooked IT bottleneck."
I look at the tapes, and yes, I know how useless they'll be in about 3 years time, we'll have migrated to a new system that isn't compatible with this. I look at the backup tapes from 1999, and how we don't even have a tape drive for them anymore, but should we need to access them we'll probably hunt them down.
What kind of disks are you talking about? Well I need over 1TB of space per backup, at the end of each month, 4 different 1+ TB backups to be stored indefinately. So I can't use floppies, CD/DVD/BRD...
Because Hard Drive Disks go through different mediums too you know, I can't plug my SCSI into a SATA. I am not entirely sure that any hard drive I use today will be accessible 10 years from now. And lets look at the prices for a 2TB hard Drive (since that'd be what I'd need). Let's say I get lucky and get them for $100 each. Tapes I can get for $30.
By using tapes we get the size we need, though the speed is slow, for the right price. Saving almost $3000 a year by using tapes.
An 800GB Native / 1.6TB Compressed LTO-4 tape costs $35. If you don't deliberately choose a ridiculous comparison, tapes really aren't that expensive.
Interrupt Moderation = Disable
Here's a real tip, disable Interrupt Moderation on your Network Adapter Cards to achieve greater bandwidth, as much as 100%+, and lower latency (the two measures of network performance) at the expense of processor utilization due to more hardware interrupts that have to be handled.
Instructions: In Windows open up Control Panel, Network and Sharing Center, click on Change Adapter Settings, open Properties on your Local Area Connection (sometimes #2, #3, or something if you have more network cards), click on the Configure button, then the Advanced tab, select Interrupt Moderation, change the value to Disabled, while there look for any settings with the word Offload and enable them all, and then click the OK button to make the changes. This will restart your network card driver and make the settings effective.
Most network cards from popular manufacturers such as Intel, Broadcom, Realtek, etc. hold network packets in a buffer until enough time goes by before raising a hardware interrupt and telling the processor, operating system, and network driver that there are packets waiting to be serviced. By disabling Interrupt Moderation you instruct the network driver and card to raise the interrupt every single time a packet comes in, thus making your processor service the network card much faster thus decreasing latency on the packets held in the buffer and also increasing bandwidth by allowing more packets to flow through faster. This increases your processor utilization by a significant amount 10-30% but if you have a recent dual, quad, hex, octo-core processor and recent network drivers that are multi-threaded with multi-core support and have Receive Side Scaling support then the increased processor utilization is negligible to your computer and if you are running a network server then network performance should be a priority anyway.
I have personally seen and tested corporate and home LAN environments using Fast Ethernet 100 Mbit/s (~11 MByte/s) go from slow 6-7 MByte/s to 10-11 MByte/s throughput, and Gigabit 1,000 Mbit/s (~100 MByte/s) go from ~30 MByte/s to 95-98 MByte/s speeds due to these changes. No other network driver setting had as much performance impact as Interrupt Moderation.
IEEE 802.1AX (aka 802.3ad, Cisco EtherChannel)
For advanced network performance improvement look at link aggregation (channel trunking, link bonding, etc.) using the IEEE 802.1AX (aka 802.3ad, Cisco EtherChannel) protocol support in your Intel and Broadcom network adapters using their Advanced Configuration Utilities on your servers to bundle from 2-8 Ethernet network adapters into one trunk to increase your performance. Just tell your network administrators to enable those features on your ports and find out if they are able to do it if your links are going to the same switch or if they have virtual switching enabled in case your links span switches. Just think about 4 x Gigabit performance if you bundle all 4 NICs on most servers.
NetCPS
You can test your own network performance with this simple but great utility called NetCPS. Just be sure to disable Interrupt Moderation on both of the computers on your LAN that you will be using for the performance testing otherwise you won't be able to achieve these numbers if one of the computers can't handle the data as fast as the other one. Try it with your laptop and desktop for example.
NetCPS - is a handy utility to measure the effective performance on a TCP/IP network.
Just execute "netcps.exe -s" on the listening system and then do "netcps.exe computername " on the other computer to use the utility to test the throughput bandwidth. For Gigabit you can use the "-m1000" switch to increase the transferred amount to 1,000 MBytes instead of the default 100. Below is an example.