Update: Valve has released new information about Steam Deck.

When Valve announced the Steam Deck, the company claimed that the system would offer "more than enough performance to run the latest AAA games at a very efficient power envelope."

While working and "working well" are not the same thing, we can take some comfort in that regard, as a Chinese user has published benchmarks taken from Steam Deck's development kit. Given that this is not a finished product, perhaps these numbers cannot be equated with what the first retail units will offer, but once things are fully optimized, performance will not be worse.

With no ability to easily run actual benchmark software on the Steam Deck, users turned to a number of games to test real-world performance. And the results were very promising, with only one, Cyberpunk 2077, as expected, giving Steam Deck a hard time.

Starting with Shadow of the Tomb Raider, the game achieved 30 fps plus with the Highest and High presets, and could easily be improved to 60 fps with a little less performance, as could Doom, The Medium preset allowed us to achieve the magic 60fps frame rate, and one step up in quality brought it down to a very playable 46fps.

As might be expected from an eight-year-old game, DOTA 2 ran very comfortably on Steam Deck, registering 47 fps at the highest setting and 80 fps at the lowest setting (output to an external monitor, as Steam Deck screens are 60 Hz).

However, "Cyberpunk 2077" proved to be more problematic. Not only did Steam Deck crash once during testing, but performance remained at the "High" 20-30 fps level, and it also froze.

Surprisingly, the leaker did not reveal the performance when lower graphics settings were applied. However, this trouble with the Steam Deck seems to be unrelated to the fact that the game recommends an SSD for best performance, and the leaker makes passing mention of the hardware's 512GB capacity (only the entry-level 64GB model has slower eMMC storage).

After three hours of use, the Steam Deck's battery appears to have dropped from 100% to 46%. We measured the temperature during the session and found that it was up to 42.6 degrees Celsius (108 degrees Fahrenheit) on the back, but dropped to a more usable 29 degrees Celsius (84 degrees Fahrenheit) on the grips.

Early adopters will get their Steam Decks in December, but those who missed that boat will have to wait much longer.