Lowest possible round-trip latency is not the Apollo's forte'.
The onboard Unison DSP is really nice (monitor/track in realtime thru UAD plugins with ~2ms latency), but the downside is that DSP support adds latency.
Apollo can get down to about 3.7ms total round-trip latency.
Apollo won't let you select the 32-sample ASIO buffer size if you're working above 48k.
Frankly, even if you could select the 32-sample ASIO buffer size at higher sample-rates, the audio would glitch.
 
If you're wanting to trigger drum samples at the lowest possible latency, right now, the best option is to run the Presonus Quantum (via Thunderbolt-3).
Round-trip latency at 96k (32-sample ASIO buffer size) is 1ms.  
Triggering your drum samples would be one-way Playback latency (a little more than half a ms).  
As long as your machine can keep up with the load, audio is completely glitch-free.
The only downside to Quantum; it doesn't have any onboard DSP for monitoring/routing/loopback-recording.
All monitoring/routing has to be done via software.
The lack of onboard DSP allows Quantum to yield such low round-trip latency.

Jim Roseberry

smallstonefan
Now, I did spill water on my motherboard Friday and we're in the process of figuring out all that was fried. Hope that Octo still works!

Ouch!

So we put in an Asrock motherboard and everything works - it was just the mobo. However, it turns out the USB3 Type C connector on this mobo is USB only and not dual purpose Thunderbolt. There is a TB header, but you have to buy an add-on card, which no one in the US seems to stock???
 
So I am thinking about another mobo, and so far can't find one to replace my Gigabyte that fried!
 
Seems like TB motherboards are few and far between. :(

Looked on Amazon and found the MB I bought that works well but I don't think it's available new anymore but they seem to have a refurbished one. And yes, TB3 MB's don't seem to be the default yet.
 
GIGABYTE GA-Z270X-UD5 LGA1151 Intel 2-Way SLI ATX DDR4 Motherboard

Jim Roseberry,
 
Thanx for the info. That Presonous looks kinda expensive, $1500? Do they have a smaller version but just as fast? FYI only looking at Sweetwater.
 

user390096
Looked on Amazon and found the MB I bought that works well but I don't think it's available new anymore but they seem to have a refurbished one. And yes, TB3 MB's don't seem to be the default yet.
 
GIGABYTE GA-Z270X-UD5 LGA1151 Intel 2-Way SLI ATX DDR4 Motherboard

The motherboard we ordered and installed doesn't support Thunderbolt without an add-on card, which cannot currently be obtained in the US. Arg!
 
I found a place that had refurbs of my old board and had one sent to me. Happy to say I just got it working today and I'm typing on it now!

user390096
Jim Roseberry,
Thanx for the info. That Presonous looks kinda expensive, $1500? Do they have a smaller version but just as fast? FYI only looking at Sweetwater.

Quantum is $1000.  
If you don't need that much I/O, Quantum-2 is $700.
Both offer the same performance.

It looked like the new Apollo x8 has built in Thunderbolt 3. They are promising less than 2ms latency. It's very pricey, about 3K, vs. 1K or less on sale for the Quantum. UAD stuff does look like a wonderful part of the package (they offer a bunch of plug ins included), but maybe this is overkill for a studio without a huge console, I'm guessing. Just wondering if I would miss the onboard DSP or not, not sure, I'm thinking I usually use my DAW's on-screen console, and am considering a control surface add-on, too.

Thunderbolt-3 won't buy any additional performance.
It's simply more bandwidth...
The Apollo is nowhere near saturating Thunderbolt-2, so it's a moot point.
 
Using their Unison DSP, you can monitor thru UAD plugins at 2ms latency.
 
Lowest Apollo goes is about 3.7ms total round-trip latency.
If you're trying to run UAD plugins at 96k (using a 64-sample ASIO buffer size), you'll mostly likely hear glitches.
The Apollo audio interfaces great, but lowest possible round-trip latency (when monitoring thru software - not their Unison DSP) is not the Apollo's forte'.

So my UAD stuff was working on my new mobo, and then just stopped. The software won't recognize the PCIE quad or the two Thunderbolt units. I have tried everything that I know how to do, and I'm going on 45 minutes hold time with UAD support.
 
Need to get rid of the "No devices found" message.
 
I so want this working for the holiday weekend...

Does your Thunderbolt controller have a USB 3.1 port (type A)?
If so, insert a Flash drive... to see if the controller is working.