Maximizing Audio Interface Performance

Another interface isn't likely to lower latency by much, perhaps by as little as half a millisecond or none at all.
 
While interface drivers do vary somewhat in efficiency, most of the latency is attributable to buffering, which has nothing to do with the interface itself, or its driver. Buffers fill at a constant rate determined by the sample rate, so a given buffer size and rate will always yield the same latency. The only way to lower latency is to reduce the buffer size or increase the sample rate.
 
How small a buffer you can get away with depends on your computer's power, the efficiency of its peripherals, the overhead incurred by background processes and hardware interrupt handlers, and the amount of processing done within the DAW.
 
With so many variables, there is no single recipe for making the computer more efficient and thereby allowing you to reduce buffer sizes. All you can do is determine the smallest buffer size that doesn't result in dropouts, and then gradually figure out what changes help in that regard. If you're lucky, you'll identify one major culprit, such as a wireless network adapter or a greedy video card that's sucking up CPU cycles. 
 
You may also decide to adopt a two-step method, wherein you do all your tracking at a very low buffer size (e.g. 64 bytes) before adding any effects to the project, and then raising the buffer to a higher value during mixing and mastering. Plugins not only increase demands on the CPU, but may also incur extra latency even with the same audio interface buffers.

If you want to get lower than 5ms round-trip latency at a 64-sample ASIO buffer size, you have two options:

• PCIe audio interface (one that allows using a 32-sample or 16-sample ASIO buffer size)
• Thunderbolt audio interface with full "PCIe via Thunderbolt" drivers/support

 
Win10 now offers "PCIe via Thunderbolt" support for Thunderbolt 3.
Have to be running one of the latest generation Z170x or X99p motherboards that supports TB3 via USB-C
Microsoft claims that TB3 support should be backward compatible with TB2 and TB1.
Right now, all TB audio interfaces are TB2.
Thus, you need a USB-C to Thunderbolt adapter.  
USB-C to TB adapters have been announced... but I've yet to see one actually available.
 

Jim Roseberry
If you want to get lower than 5ms round-trip latency at a 64-sample ASIO buffer size, you have two options:

• PCIe audio interface (one that allows using a 32-sample or 16-sample ASIO buffer size)
• Thunderbolt audio interface with full "PCIe via Thunderbolt" drivers/support

Or settle for around 6 or 7ms round-trips and get an RME USB/firewire interface.

To which has to be added 1ms for every foot between ears and monitors of course.

If someone can't cope with playing with their instrument speaker or stage foldback six feet away from them, reducing latency below 6ms is unlikely to help them much.

On my RME UFX @ 64 buffers @44.1K/24 (connected via UB) SONAR reports 5.1ms RTL.
 
Also if you must track with FXs on other tracks, you can always freeze those other tracks.

tlw

Jim Roseberry
If you want to get lower than 5ms round-trip latency at a 64-sample ASIO buffer size, you have two options:

• PCIe audio interface (one that allows using a 32-sample or 16-sample ASIO buffer size)
• Thunderbolt audio interface with full "PCIe via Thunderbolt" drivers/support

Or settle for around 6 or 7ms round-trips and get an RME USB/firewire interface.

To which has to be added 1ms for every foot between ears and monitors of course.

If someone can't cope with playing with their instrument speaker or stage foldback six feet away from them, reducing latency below 6ms is unlikely to help them much.

 
FWIW, I play out quite a bit.
Once you start to venture too far away (without IEMs), you can *really* start to feel the lag (latency).
Can you compensate? Yes.  Does it affect feel?  Absolutely.
Lower latency feels tighter.
I'm pleased with the RTL of my Fireface UFX.  
That said, if I can get the RTL lower (which feels even better), I'm all for it.
 
Don't agree that lower latency feels "better"?
Load up your favorite piano sample library.  Play it at a 256-sample ASIO buffer size.
Now drop the ASIO buffer size to 64-samples.
Which feels more immediate/responsive?
To my ears/sensibilities... it's easy to hear/feel the difference.
 

I've done more than my fair share of gigs where someone's bass amp is 20 feet away from me and vocal/acoustic instruments only in the foldback. Keeping in time becomes as much a matter of watching them as listening to them at that range. This being in a band with no drums, so no-one in the middle of it all to act as a fixed reference point.

I can't handle bass or guitar at much over 10ms latency, my timing just collapses and eveything feels wrong when I feel the fingers hit the string then the note sounds after a distinct gap. Walking out among the audience at the end of a 150' cable might have worked for Albert Collins, but not me.

I move around a lot when playing...
Tried a set of non molded IEMs.  Every time I'd move... they'd pop out of place.
 
Without IEMs, on larger stages it's easy to get more than 20' from your monitor.
If you roam over to the guitar player and your not in his/her monitor, it can be harder to hear yourself... and then you're dealing with significant latency.
The advantage to that much physical space: Far less prone to feedback issues

I like where this thread is going, because some have chimed in with real world examples, like how far you are from your speakers before you lose your "lock" with yourself or your bandmates. If you do some quick math, sound travels about 1 foot per millisecond (700mph x 5280 ÷ 3600 seconds in an hour ÷1000ms=1.02). So ask yourself how far away from an amp can you play before you start to feel the lag? 10ft?  20 ft? That's how many ms of latency you're feeling. When listening to monitors , how far away are you? factor that into your RTL. So if you are , say 8ft and 20ms RTL ,you are really feeling 20 ms RTL + 8. If 20 is the"magic " number where yo really start experiencing it, you should be shooting for 5-10 ms. if you can hit this sweet spot, you're in good shape. Less than 5ms RTL will most likely be imperceptible.