>Under Windows 10, what are you mostly using to optimize disk performance. Before, we use to align the sectors with built-in tools and things like that. Anything specific we should consider for Windows 10?

Generally there are 2 parts to questions like this:

1. Do I need to get faster hardware?

2. How do I best make use of the hardware I have (or that I'm going to purchase)?

Hardware
For current workstations, disk hardware performance is as follows (fastest to slowest):

1. System RAM used as Windows disk cache (or optionally, a RAM disk)

2. SSD or Intel Optane on NVMe interface

3. SSD on SATA interface

4. Hybrid drive (HDD with internal SSD cache) on SATA interface. These are less common these days since high-capacity SSDs are coming down in price

5. HDD on SATA interface

Optimization

1. System RAM:
- Have lots of it
- Enable write caching (Device Manager...Disk drives...Policies tab). For safety this usually requires that a desktop computer have a UPS, or is a laptop with a charged battery
- Windows already uses available RAM for a read disk cache (not configurable)

RAM disk: has similar performance improvements as the Windows disk cache. Ones with physical dedicated RAM are rare and expensive. More common is to use part of system RAM as a temporary RAM disk. This may be an option for applications that require a dedicated chunk of RAM as a high-speed file system. However, I've never seen such a case, in general the Windows disk cache is smart enough and is more flexible and adaptive.

2. Consider hardware caching if your persistent data storage is on SATA interface e.g.
- Intel Optane or equivalent (3DXPoint cache)
- Intel Smart Response or equivalent (SSD cache)

Windows Server OSs offer tiered storage/Storage Spaces, which is (amongst other things) another way to use SSDs as caches for slower persistent storage. Apparently it was available (but hidden) in at least one version of Windows 10 but may not be any longer.

3. Optimize your existing hardware:
- Don't let any drive get full, or nearly full. This can cause huge performance losses, regardless of hardware and interface types. My rule of thumb is 10% free space is yellow alert, 5% free space is red alert
- Consider whether Windows Prefetch and Superfetch are suitable for your hardware: https://helpdeskgeek.com/help-desk/delete-disable-windows-prefetch/
- Make sure your system has the latest BIOS/motherboard/chipset drivers installed, from the manufacturer's support site

- HDDs: periodic defrag can be useful. If you have RAID, check the manufacturer's recommendations for the RAID level(s) you have implemented
- HDDs: speed freaks used to "short stroke" hard drives e.g. https://www.pcworld.com/article/255224/how_to_partition_your_hard_drive_to_optimize_performance.html . This reduces average seek times and utilizes the part of the hard drive with the highest data transfer rates

- SSDs: ensure TRIM is enabled: https://www.windowscentral.com/how-ensure-trim-enabled-windows-10-speed-ssd-performance
- SSDs: be aware that low-end RAID hardware may not support TRIM for RAID1, which long-term is not a good thing e.g. https://www.dell.com/support/article/ca/en/cadhs1/sln301552/solid-state-drives-in-irst-raid-1-may-have-degraded-performance?lang=en
- SSDs: defrag is basically useless or worse than useless (i.e. unnecessary drive wear)

RAID

Generally workstations only need or support up to 2-drive RAID: either RAID0 or RAID1. RAID0 (striping) can put up some impressive performance numbers but has zero fault tolerance: any fault on either drive and you lose the whole array. RAID1 (mirroring) with 2 drives is good insurance against hardware failure, but as noted above may not support TRIM for SSDs.

If you have more physical drives and/or other RAID levels, follow the manufacturer's recommendations.

HDDs used in RAID arrays must support TLER for reliable operation.

Background Applications

Regardless of your disk subsystem hardware and optimization of its configuration, performance can be improved if you can reduce its I/O load from background applications. If you can avoid running certain background applications at all, then not only is system I/O load reduced, but system RAM is freed up for use by the Windows disk cache.

Background apps can be stuff running that you're not actively using e.g. you can close Outlook if you need maximum performance for something else. Or it can be unnecessary Windows services - either parts of Windows itself that you aren't using, or "bloatware" that comes with many OEM computers these days.

With Windows 10 in particular, disable Cortana, and go through your Privacy settings to protect your privacy and minimize background processing.

Antivirus software is incredibly invasive and can cause a huge I/O load, especially when it decides to do a full system scan during work hours. Schedule any such scans outside of working hours, or disable scheduled scans and do them manually instead. If you're using 3rd-party AV, consider going back to Windows Defender instead; the general consensus is it may not block as many attacks as some others, but it is the least invasive and integrates best with Windows (as you would expect from a Microsoft product). As long as you don't regularly browse dodgy Web sites (or have teenage children who don't care about security) then Defender works fine.

Check the operation and timing of your backup solution(s). So-called "real time" or "continuous" backup can impose a heavy I/O load. The built-in File History is nominally "continuous", if you're using that you might want to check its settings. Some cloud backup applications work similarly, you may also check their settings to see if they can be made to operate outside regular hours.

The performance of Windows mainly depends on its disk subsystem; it's usually the bottleneck for business applications. If it can't keep up you get sluggish performance and "Not responding..." warnings. Most articles about "how to speed up Windows" essentially boil down to ways to improve your disk subsystem or reduce its I/O load.

Speaking of which, various "free" Windows optimization apps are usually worse than useless on Windows 2000/XP or later and are often fronts for malware or grayware. You can use utilities such as Malwarebytes' Anti-Malware to identify and remove these parasites.