Version 4.2.1 is out now and has many speed enhancements over the initial 64bit release (link at the bottom).
I stumbled upon this last night after not imaging for a couple weeks due to weather. There are no release notes on the version, but I’ve been waiting for this since I started, so I went ahead and downloaded it. So far, so good. The look and feel are basically the same with only slight visual tweaks.
One of the standing problems with Deep Sky Stacker has been the lack of a 64bit version. Since Windows 10, virtually all PCs come with 8GB RAM, and fast processors. Having only a 32-bit option for DSS only allowed for the use of a maxiumum of 4GB of RAM – in reality it was much less due to other system limitations.
The application’s inability to handle large amounts of data, faster, prevented those of us using DSLRs or other high resolution cameras from the benefit of things like superpixel, and more importantly drizzle. Even an attempt to start stacking an image with the Drizzle option selected would result in an out of memory error!
The new version is 4.1, and it is available in 32-bit and 64-bit. Be sure you are using a 64-bit PC and operating system prior to trying to jump to the 64-bit version. Trying to install the 64-bit version on a 32-bit PC won’t hurt it, it just won’t itstall. Some of us Astrophotographers are still using older laptops due to driver compatibility for our equipment, limiting our experience. I admit that if I didn’t have an IT background, I would have probably stuck to a 32-bit Windows 7 myself due to the amount of finagling I had to do with drivers. I’ve since moved to using separate PCs for scope control and image processing, but keep both up to date with Windows 10 (despite Microsoft’s screw-up with Spectre/Meltdown in January). If you’re not using a newer PC to process your images, you may need to stick to the 32-bit version.
To find out if you can utilize this feature, click on Start and search for Control Panel. Double-click the System icon. For Windows 7, click Start–>Control Panel, and double-click the System icon. You’ll be presented with a screen similar to the one below.

The most important field is the system type, followed by the installed memory. If the system type says 32-bit Operating System, the 64-bit option is out for you without at least upgrading your version of Windows. Next, your system RAM really should be a minimum of 8GB. You will gain a small advantage using 64-bit DSS with a 64-bit OS and only 4GB RAM, but it is a very small advantage. 8GB and higher is where the advantages will really stand out.
One other variance of note on this – If you see that you have 8GB or more RAM, and you have a 32-bit operating system, you should consider upgrading Windows to a 64-bit version unless you have specific applications holding you back. With a 32-bit operating system, you’re limiting yourself to the use of only 3GB RAM – not just for Deep Sky Stacker, but for everything.
Check your system, and check out the new version. I only installed it last night, but I’ve processed several data sets with various options I previously was unable to use without issue. Use the Link below to the download page – and please donate if you have the means. We have a lot of free software options for Astrophotography, but very few would exist without donations. I have no affiliation to DSS or it’s creators. It’s just an application I’m constantly using and highly recommend.
Download Deep Sky Stacker 32-bit and 64-bit
Clear Skies, Bleary Eyes – KA