Why is there no laptop certified under 64-bit?

Question

Ubuntu has a hardware certification program (http://www.ubuntu.com/certification).

If you search under Release 11.10 and laptop, you will find that all are certified under 32-bit and none under 64-bit. In Release 11.04 there are only two out of 107 laptops 64-bit certified.

Why is that the case? And: if a laptop is only 32-bit certified, are there chances it will fail under the 64-bit release?

Answer 1

By default all client systems are certified for 32-bit, unless the vendor specifically requests 64-bit certification. Servers, though, are only certified in 64-bit.

This reflects the fact that the recommended (i.e. the default you get when you go to download) Ubuntu version for client systems is the 32-bit one.

This in turn obeys a variety of factors, not all of which I'm aware of. I know, for instance, that Flash support (which prior to Oneiric and multiarch support was suboptimal on 64-bit systems) meant that recommending 64-bit and expecting a great end-user experience wasn't feasible.

As Ubuntu moves towards defaulting to/recommending 64-bit, expect to see certification transitioning to 64-bit instead. A capabilities survey revealed that about 80% of systems are 64-bit capable nowadays. This becomes a necessity as more systems ship with over 3 GB RAM, which is the reasonable limit for the 32-bit kernel. Also this is made possible by the fact that the end-user experience on 64-bit has improved considerably as of late.

Two specifics about certification: Only one arch is certified because it would be quite burdensome to certify both for all systems. Also, we have seen cases where a system would work under 32-bit Ubuntu but fail under 64-bit (and vice-versa), so don't be 100% certain that it will work (you can be highly confident, but if you want to deploy on a non-certified combo (architecture/machine) please test before you buy).

Answer 2

If the laptop is certified under 32-bit, but has the ability to run 64-bit software, then chances are it'll work just fine under the 64-bit OS.

However, these is the following potential issues.

1. Precompiled binaries may not be available for 64-bit. Further, a 64-bit version on a binary may not be tested as extensively.
2. These binaries are likely to include- Various drivers and other software such as flash.
3. 64-bit software in general is likely to be tested less extensively. (However, I've never run into an issue.)

EDIT: I figured someone else would take up answering "why" it's like this.
All I can do is speculate.

1. It's obviously more expensive to test both.
2. There is less demand for both testing.
3. The 32bit version is generally more supported overall. It's only natural that this flows over to certification as well. (ie. 32bit is labeled as "recommended") Why does Ubuntu Download recommend 32-bit install?