There are a million little applets and forms out there to do byte conversions, but for whatever reason this is the one I have bookmarked. I'm sure full time performance testers can do this stuff in their head, but us part-timers need help every now and then. Perhaps I like it because it's a simple clean interface, and it shows me the conversion rates:

1 Byte = 8 Bit
1 Kilobyte = 1024 Bytes
1 Megabyte = 1048576 Bytes
1 Gigabyte = 1073741824 Bytes

Do you have one you prefer? Or perhaps another similar simple tool you use when testing?

Many times when performance testing, I'll manually calibrate my performance test script by loading the page manually and comparing those load times with those generated from my test tool. Doing this with a load of one user allows me to get an idea of how much my tool is skewing the numbers. Often, I find the tool is just a tad bit worse in terms of response times. If it's too far off, that normally tells me something is wrong.

Today's tip comes from Senthilnathan over at Testing-Virtuoso. Senthilnathan provides a very succinct set of tips for network performance testing. From that post, some tips for performance counters in Perfmon:

Network Interface\Bytes Received/Sec
Network Interface\Bytes Sent/sec
Network Interface\Bytes Total/sec
Network Interface\Current Bandwidth
Network Interface\Output Queue Length

If the Network Interface\Bytes Total/sec is more than 50 percent of the total network utilization, then your server is having some problems under peak load conditions.

Correlate the network counter values with Physical Disk\% Disk Time and Processor\% Processor Time utilization. If the Disk\% disk time and %processor time values are low and the network queues are high then there might be a problem with your network card/ bandwidth.

I love seeing what counters performance testers look at. If you have some different counters you use when testing, feel free to share.

PAL, which stands for Performance Analysis of Logs, is a free tool for pulling apart Microsoft log files (IIS, MOSS, SQL Server, BizTalk, Exchange, Active Directory) and analyzing them. The tool generates HTML reports based on recommended performance counters and shows when thresholds for those counters have been exceeded. You can also setup your own custom thresholds in the tool.

Fiddler is a Proxy which logs HTTP/HTTPS traffic. You can set breakpoints, change data, and perform event-based scripting. Fiddler is freeware and works with just about any browser.