Hey all. Due to several hardware/OS-related reasons, I found it necessary to switch from my longstanding Saffire Pro 40 (FireWire) interface to its USB counterpart, the Scarlett 18i20.
 
While overall the performance is exactly as expected and a very clean transition to the Scarlett, I have noticed some differences and my guess is that it has more to do with the connection type (USB vs FireWire).
 
The Pros: just like the Saffire, the Scarlett's latency is little-no-none. (Yes, there's ALWAYS latency, but both buggers are fast and latency during tracking isn't noticeable). I'd always set the Saffire at 64 samples when tracking, then bumped up to 512 or 1024 when mixing. The Scarlett's settings are in milliseconds as opposed to samples so that took a little getting used to, but I'm still able to track at 2ms without any clicks/pops/dropouts, which is on par with the Saffire.
 
However, there are some drawbacks:
 
1) The Scarlett does not have a loopback function in Mix Control, whereas the Saffire did. While I didn't use the feature very often, it was nice to be able to record what my PC was "hearing", as in, set up loopback, arm/record a track, then play something on YouTube, thereby capturing the audio. It seems the only way to do this with the Scarlett is to manually set up a cable patch from physical outputs/inputs on the interface.
 
2) While it's often been said that Windows doesn't allow applications to share ASIO drivers simultaneously, I was always able to do this with the Saffire. (I'd select the "share drivers" settings within SONAR first, of course.) I could have an open session in SONAR, export audio, then play it back in Windows Media Player without having to close out SONAR. Likewise, I could have a browser open and jump back and forth between YouTube and SONAR without a hitch. No longer the case. If SONAR is open, everything else is locked out.
 
3) I have an Eleven Rack connected to the Scarlett via SPDIF. I also have the Eleven Rack connected to the PC (USB connection) so I can run the Eleven Rack Editor (change amp models etc. without having to use the hardware's knobs/buttons). With the Saffire, I noticed some clicking/popping when tracking with the Eleven Rack, so I ended up changing the clock settings on the Saffire from Internal to SPDIF, and that did the trick. While I haven't noticed the clicks/pops thus far with the Scarlett, I have noticed that I cannot set the Scarlett to SPIDF and still use it within SONAR. SONAR then recognizes the Eleven Rack as my ASIO device and I'm not able to select the Scarlett. Didn't work that way with the Saffire.  Hopefully I don't notice any clicks/pops this time around - and that would inevitably be better anyway since I'd no longer have to change clock settings and could just keep the Scarlett set at Internal. But if I run into sync settings again, not sure what my options are, aside from getting rid of the SPDIF connection and running analog outs from the 11R into line inputs on the Scarlett.
 
4) For whatever reason, it seems to take the USB connection a while longer to fire up when starting Windows. I used to hear the "welcome" jingle when starting Windows, now I just hear a couple static pops, as if the Scarlett is fully fired up and ready by the time Windows startup plays the audio file. Not a big deal of course because who cares, but still odd.
 
5) Audio engine dropouts. The Scarlett will sometimes not be recognized right away when I launch SONAR and will require either (a) closing SONAR, firing up Mix Control, make sure settings are correct, then re-launching SONAR, or (b) powering off/on the interface to get everything reset. Doesn't happen often and once it's there, it stays there (i.e. I don't lose the connection once SONAR is live), but still goofy.
 
So it seems to me that this is all USB related, since that's the primary difference between the two interfaces. I know that FireWire is pretty much a dead technology, and since Thunderbolt isn't heavily supported in Windows, it seems USB is really the only viable interface option at this point. It's too bad, because FireWire was always rock solid for me on the old setup, and I'd still be using it were it not for IEEE 1394 chipset/motherboard/Windows 10 compatibility issues.
 
Are these types of issues typical of any USB interface and just something I need to get used to? Or are others on here using the Scarlett (or other USB) interfaces and don't experience any of the scenarios I've described?

I used to have a Saffire Pro 40.  I now have USB (Roland Octa-Capture).  I get more reliability with the USB than I did with Firewire (and I had a compatible listed T.I. chipset in the PC).  At least with the Saffire Pro 40 I had Firewire was iffy at best and many times a PC reboot or reconnection was required.   I should note that before the Saffire Pro 40, I had an Alesis IO26 which was Firewire too and it was rock solid.  I switched over in 2004 so newer Saffire Pro 40 drivers may have fixed some of these problems - just my issues. 
 
On the USB, make sure you are connecting directly to a port on the PC and not to a USB hub.  USB hub's, especially the non powered types, are to be avoided.  A good quality USB cable is also needed and it needs to be certified for USB 2.0.   If you are connecting to a USB 3.0 port, some USB 2.0 devices, although supposed to be compatible with a 3.0 port, are iffy, so make sure you are using a 2.0 port.  I would try different USB 2.0 ports, such as a front panel port if you are using a rear port (or the other way if using a front panel port).
 
Run the free Resplendence Latency Mon just to verify all is OK.
http://www.resplendence.com/latencymon
 
Edit/Added:  USB Tree View is another utility that can help.  It lists what is on each port.
http://www.uwe-sieber.de/usbtreeview_e.html#download
 

Thanks for the feedback. Strange that the Saffire was janky for you but rock solid for me...I guess that's what we get for having PCs. Tons of options and much less expensive, but configuration anomalies abound!
 
I failed to mention it, but yes, I'm connecting both devices to USB ports, not hubs. Also, both for the Scarlett and the Eleven Rack, documentation states that they need to be plugged into USB 2.0 ports, not USB 3.0. Since this is a new board, most USB ports are now 3.0 so my 2.0 options are limited.
 
Thanks for the tool resources; I'll give them a run.
 
I think I'm going to give the Saffire another shot by picking up the PCIe FireWire card that's recommended for Focusrite products in Windows 10. Although that particular card has known compatibility issues with my Z170 chipset, if all else fails I can just return the card.
 
It should be noted that none of my issues are earth shattering and I still have a very usable setup; it's just that things were much more flexible and convenient with the Saffire and I'm hoping I can get that working on my new setup.

The PCI Firewire card I use with my Pro 40 is from Startech.com

I didn't have any issues with my Windows 7/Z68 setup, but Windows 10/Z170 has some known issues with FireWire/Focusrite and there are only a handful of IEEE 1394 chipsets that have been shown to work. The one I'm picking up has the Texas Instruments chipset known to be most compatible for audio interfaces, and even though it hasn't worked on some Z170 boards, I'm hoping that mine will be the exception. I used the newest BIOS and chipset drivers when I built the PC so fingers are crossed!

I own a Scarlett 18i20, and while I haven't used it in a way that would cause problems 1-3 in your list, I can say that 4 and 5 are not issues for me. I did have a few problems with settings when I first got it (which could have been user error), but since then there haven't been any issues at all. I usually keep Mix Control up to manage my monitors, etc, but Sonar seems to get along great with the Scarlett for me.
 
Cindy

Yeah, in most cases I don't run into any issues either. The dropout issue doesn't happen very much at all and is rock solid the vast majority of the time. Kinda weird that my USB port isn't "waking up" in time for the Windows welcome ditty, but whatever. No big deal.
 
Of course, for me, issues 1-3 are what I really liked about the Saffire, especially 1 & 2, since there's a workaround for the Eleven Rack (bypassing SPDIF and just running analog outs/ins) if I do run into clicks/pops.

I have the 18i20 and it has been rock solid for like two years (since I bought it).
I run it at 32 samples when tracking and 64 when mixing and no problems at all.
I run Sonar or my other DAW, export my mix, then open it in Ozone 7 work on it (with DAW open), export my file and play it against other tracks in WMP or itunes (DAW and Ozone open).
While DAW is exporting mixes, I watch something in youtube and no problems either.
Is what I describe that you are not able to do with the Scarlett?

Sonico
I have the 18i20 and it has been rock solid for like two years (since I bought it).
I run it at 32 samples when tracking and 64 when mixing and no problems at all.
I run Sonar or my other DAW, export my mix, then open it in Ozone 7 work on it (with DAW open), export my file and play it against other tracks in WMP or itunes (DAW and Ozone open).
While DAW is exporting mixes, I watch something in youtube and no problems either.
Is what I describe that you are not able to do with the Scarlett?

Yep, that's exactly what I can't to. If I have a session open in SONAR and I open up a web browser and try to play something on YouTube, there's either (a) no audio from the browser or (b) an error message from YouTube stating an error occurred during playback. Same thing if I open up iTunes and try to play something, nothing happens. Also true with any other application that uses audio drivers (Premiere Pro).
 
Likewise, if I have another application open that's using audio (such as Chrome w/YouTube) and I attempt to open a session in SONAR, I get an error message stating that SONAR is unable to open audio record device, etc.
 
I know it's been said that Windows doesn't support multiple audio devices simultaneously, but in the case of my Saffire it did, and apparently in the case of your Scarlett, it does, too!

It's not multiple audio devices simultaneously, but a single audio device with multiple apps using it at the same time.
Not sure if it helps but I disable any integrated audio driver in my computer (the one on the motherboard, the one in my touch screen monitor, etc) to avoid potential conflicts.
I don't remember doing anything else, it just works
I haven't updated my signature in a while but I'am using windows 10 64bits
Are you using the latest beta mix control and driver?
Mine is Mixcontrol 1.9.64.12 and driver 3.2.292 with 1056 firmware