The HP Slate will use Windows 7, but what isn't known is which chip will power the Apple iPad rival from Hewlett-Packard.

This is an important question, as there's a world of difference between an Intel Atom processor and, let's say, a low-power Core 2 or Intel's latest-and-greatest chips based on the "Nehalem" design, referred to commercially as the Core i3, i5, and i7. Atom chips (with one exception) use a single-core processor--which can struggle under moderate to heavy workloads--while the more powerful Core 2 and i series chips use two processing cores.

HP has been careful not to reveal the silicon inside. And the company has declined to answer queries about internal silicon specifics. So, let the guessing games begin.

In order to make an educated guess at what HP may have in store, here's what Phil McKinney, chief technology officer at HP's Personal Systems group, said last month (see video) about the HP Slate: "North of what a smartphone is, smaller than a Netbook and notebook. Something thin and light but allowing (consumers) to have that rich media experience. They can do everything on that one device versus having to carry a variety of devices. I want to browse, I want to watch my movies, I want to be able to listen to my music, I want to read magazines and books."

Well, all of those things can be done on an Atom-powered Netbook, but the experience isn't always smooth--even when using the new "Pine Trail" Atom. The upcoming Moorestown Atom is a different beast and is slated to power tablet-like (i.e., large-screen) smartphones. So, Moorestown is also a possibility.

And anyone in need of further proof of Moorestown's viability, just check out the Open Tablet 7, which is based on Moorestown.

And just to keep the discussion interesting, there is already some chatter about a future Atom processor on a Japanese-language PC technology Web site. That site, PC Watch, speculates that upcoming ultrathin Sony Vaio laptops are possible candidates for the processor.

That leaves us with a bevy of low-power versions of more powerful Intel processors: the Core i and Core 2 Duo chips (as mentioned above) and the Celeron and Pentium processors. The ultra-low-voltage (ULV) Core 2 Duo SU7300 processor, for instance, delivers stellar battery life. In a laptopmag.com review, an HP Pavilion laptop lasted more than nine hours.

Finally, low-power Core i5 and i7 processors will be appearing in new laptops in the coming months, but whether these are suitable for a tablet device is questionable.

Whatever chip HP has decided to use, it will not be an insignificant choice as the iPad's operating system coupled with the Apple A4 processor will be no slacker.