Yesterday we showed you how to install Android 4.0 Ice Cream Sandwich on a Nexus S — and now we have a hands-on video of ICS running on Google’s superphone of yesteryear (embedded below). If you’ve already seen a video review of the Galaxy Nexus, you won’t be too surprised by what you see — but if you’re curious about how ICS will work on older phones, or if you own a Nexus S but you’re holding off for an official build, then you might find the video very interesting indeed.

Update 28/11/2011: An alpha build of CyanogenMod 9 is now available, and you’re strongly recommended to use it over the custom ROM shown here (the Kwiboo build).

Basically, the 1GHz Hummingbird processor (Cortex-A8 + SGX 540 GPU) found inside the Nexus S is more than strong enough to power Ice Cream Sandwich — but, unsurprisingly, it isn’t quite as smooth as the Galaxy Nexus. The framerate isn’t quite as high, and so instead of totally-smooth transitions and icon jiggles, it’s sometimes slightly choppy. As you can see in the video, though, it’s still very usable — and only marginally less snappy than Gingerbread. For a custom, non-official build, ICS on the Nexus S is very impressive.

It’s important to note that the Nexus S is only a year old, though — and its hardware spec, along with its doppelganger the Samsung Galaxy S, was market-leading at the time; you would expect Windows 7 to run fine on a computer that’s three or four years old, so why not Android? Regardless, the performance of ICS on the Nexus S indicates that the Galaxy S 1 & 2 should run ICS perfectly, as should its contemporaries — HTC Desire HD, the Droid X2 — and any recently-released smartphone (Razr, Bionic, and so on).

The excellent performance of ICS on the Nexus S does cast a little doubt over Google’s claim that the Nexus One is too old for Android 4.0, however; the One’s hardware isn’t that slow. As we have covered before, this might simply come down to the lack of ROM space rather than raw grunt. It’s a shame, though: The Nexus One is just two years old, and a lot of people still use it — or one of the many phones based on its hardware spec (HTC Desire, HTC Evo 4G, Droid Incredible) — and ICS is so different from its predecessors.

The first minute of the video is part of the installation process — skip it, if you just want to see what ICS looks and feels like on the Nexus S. Face Unlock isn’t shown, by the way, but it does work.

Check out more of our Ice Cream Sandwich coverage