ASIO Reported Latencies seem way too high?

Hello all,
     I know there are other threads pertaining to this topic, but I didn't want to hijack, so I started this one.  My system specs are in my footer, and I'm using a Focusrite 2i2 audio interface with ASIO drivers. When I go to Preferences/Driver Settings, in the Mixing Latency section, the Buffer Size slider is greyed out, so I click the ASIO Panel button (which for some reason I have to click twice before it opens).  This brings up a very barebones Focusrite ASIO Driver box containing a Buffer Length slider which I have set to 7 msec.  This gives me an Input Latency of 15.3 msec, 676 samples and an Output Latency of 22.3 msec, 985 samples for a Total Roundtrip of 37.7 msec, 1661 samples.  The only way I can get the Total Roundtrip below 10 msec is to set the Buffer Length slider to 1 msec.  To me, a Total Roundtrip of 37.7 msec seems way too high, but maybe I'm using a wrong Buffer Length?  I want to get my Total Roundtrip below 10 msec before I start using a MIDI keyboard to trigger softsynths, or use any amp sims in realtime, and I feel like a Buffer Length of 1 msec is way too low.  FWIW, my buffer sizes in the Sync and Caching tab are set to 512.
     Any thoughts or suggestions, or does this all sound perfectly acceptable?  Thanks in advance!

The numbers on the slider are just numbers not milliseconds. They just indicate a relative increase or decrease of in latency.

What Sample Rate are you using with your interface?
 
And, for whatever the worth, my input latency and output latency for my Presonus AudioBox 1818 VSL are each 4.7 milliseconds (224 samples), and the total roundtrip latency is 9.3 milliseconds (448 samples).  
 
To achieve that, I have a Sample Rate of 48 k, and an ASIO Buffer Size of 128.
 
You might also consider trying a Sample Rate of 44.1 k, just to see if that also removes this issue.  Make sure the sample rates match, between the interface and Sonar.
 
Bob Bone

The posts above are accurate. When I finally found pictures with screenshots of that ASIO panel it became more clear. There were a lot of posts saying "I have buffer set at 0ms, but see latency of Y milliseconds," so please consider those "numbers" as guidelines (not values). The values listed at the bottom of Preferences->Audio->Driver Settings within X3 are the accurate system latency.

Latency is only an issue when relying on monitoring through the DAW while recording. During playback only, latency is not an issue. This is fortunate as some plug-ins designed for mixing and mastering add significant amounts of latency. It may also be necessary to increase the number of buffers used by the interface to reduce the CPU load during the mixing process.

School and Cactus, that's helpful information; thanks a lot! I'll try to have a go at that Centrance RTL test in the next couple of days. I'm mainly a synth and piano guy, so everything is smooth sailing for now. I do plan on tracking guitar with amp simulation in the near future, however, so I do want to make sure my latency is as low as possible. The Focusrite 2i2 does have a zero latency monitoring feature, so I'll have to explore that a little further when/if it becomes necessary. Thanks for the help!

A few thoughts/corrections:
 
- Cactus' link to Centrance is the way to go to measure your true RTL. Subtract what SONAR reports from what CEntrance measures, and that's your Manual Offset. But it only corrects recording (i.e. Input) latency after the fact and has no bearing on real-time latency.
- Buffer size affects outbound latency, and outbound latency will affect soft synths.
- Latency also includes A/D/A conversion and input bus latency, and this is generally the largest part of what the driver doesn't report. This typically adds about .5ms each way, and is why manual offsets are often on the order of 40-50 samples, though higher is common (especially for USB2 interfaces), and lower is possible if the driver programmer accounts for it.
- Soft synths are also subject to MIDI "latency", including the keyboard scan time, MIDI transmission time, and SONAR's time to echo live MIDI input to the synth. This can be quite variable, depending on your MIDI interface/driver performance. Typically this is adding another 4-6ms.
- Ignoring MIDI latency for the moment, most users agree that a true ASIO RTL under 10ms feels pretty decent for playing soft synths or monitoring analog inputs in headphones. It's quite possible to get used to more latency, but I think most would start to be bothered by anything over about 15ms. 37ms would be unbearable for most.
- Most decent interfaces can perform well with an ASIO buffer of 128 samples, giving a true RTL of 6-8ms at 44.1-48kHz, depending on the the driver and what bus is used to connect to the DAW. And so long as the Deferred Procedure Call (DPC) latency of the PC is reasonable (preferably consistently under 200 microseconds), performance should be smooth and click-free for the tracking phase of a typical project.