The Droid Guy reports that a device carrying the ID string GT-P5200 has been spotted on Antutu benchmark database, hitting a whopping 24,616 points with a clock speed of 1.6GHz and using Android 4.2.2 Jelly Bean. Incidentally, that's not that far from the 24,247 we reported for the Samsung Exynos 5 Octa a while back at MWC.
An inside source told Sammobile that the GT-P5200 could be an early prototype of the Samsung Galaxy Tab 3 10.1. That is backed by the fact that Samsung no longer use the GT-PXXXX string as its model number, opting instead for SM-Txxx. The site mentions that the highest Antutu benchmark figure reached by any mainstream commercialised table is that of the Samsung Nexus 10 (which has a dual-core Exynos 5 Dual, the 5250) which managed to hit around 13K.
Should this be an early prototype, it is likely that there will be further improvements and tweaks that may push the unannounced tablet nearer to the 26K mark, roughly what would be expected from the Snapdragon 600 or the Exynos 5 Octa.
Given that the smaller Galaxy Tab 3 7.0 has just been launched, with some rather disappointing hardware specifications, one could argue that the follow up to the Galaxy Tab 2 10.1 might just as well be drab.