Talk of Android 4.3 for the Samsung Galaxy S 4 had been increasing in frequency lately. Just in the past week we have seen rumors suggesting the update would begin arriving in late-November and we saw an update schedule leak by way of a French carrier. Well, it looks like the latest has arrived in the form of an Android 4.3 test build for the Galaxy S 4.

Said test build has recently leaked and has arrived as version I9505XXUEMI8. As evidence of the version, this test build is intended for the GT-I9505, which is the unlocked European model. There is an option to download and install this build, but as always, you should use test builds with caution as there could be issues.

With that in mind, the folks at SamMobile have said they have found it “really stable” and to be a build that has “received a significant boost” in terms of performance. In fact, they go on to say that it is “much faster and lag free than Android 4.2.2.” Further details point towards most of the changes being under-the-hood with a few minor tweaks to the user interface.

Otherwise, those same rumors suggesting a late-November release for the Galaxy S 4 also pointed towards the Galaxy S III and Galaxy Note II getting Android 4.3. So far we have yet to see any test builds leak for those latter two devices, but if there is anything to take from the Galaxy S 4 leak — it is that Samsung appears to be making progress towards the official release.

Of course, there is the other side of these updates. Once Samsung has them ready they go to the carriers for approval. Or in simpler terms, just because Samsung appears to be making progress and just because we have seen rumors pointing towards November — specific carriers could end up having a different timeline for release.