Palm is warning that installing on the Palm Pre smartphone an unauthorised kernel, created by two hackers to spur the phone's performance, will likely void the warranty. An online video shows a customised Pre responding immediately and smoothly with multiple applications active, and an "insanely fast" web browser.

The overclocking patches, one for 720MHz and one for 800MHz, are the work of hackers unixpsycho and caj2008. They dubbed the code an "optimised kernel" for webOS 1.4 only on Palm Pre or Palm Pre Plus, not the Pixi smartphone models.

The patches come with several warnings. "Do not use on any other OS version or you may may frakk your Pre. You must read and abide to all the below guidelines. This may shorten the lifetime of your cpu so be forwarned and to due [sic] so will be at your own risk. Use of this software may result in the potential voiding of your warranty. Our initial data shows good safety, and no significantly higher battery drain or cpu temperature as a result of use of this kernel (data still being collected)."

Palm issued its warning on Sunday. "Palm is working hard to improve the speed and performance of webOS, as shown in our recent 1.4 update. While we appreciate the effort the webOS community has put forth to try and help us along that path, the use of this application is neither endorsed nor recommended by Palm and will likely result in a voided warranty. Palm encourages webOS users to let Palm release official updates that provide safe, reliable, over-the-air features that improve their device in a number of areas, as we have in the past at a rate of approximately once per month."

The Pre CPU is a Texas Instruments OMAP 3430 chip, which is based on the advanced Cortex A8 core from ARM coupled with the PowerVR SGX chip for 2D/3D graphics and video. The 3430 can run at 600MHz but Palm reportedly "underclocks" it to run at 500MHz on the Pre smartphones.

Palm tweaked software performance when it released webOS 1.4, at the end of February. But clearly not enough for its hardcore users.

Fellow coders and Palm enthusiasts welcomed the unauthorized code, confirming substantial speed boosts. "Nothing short of awesome so far, no heat and much better battery performance," posted aezrilov, at Precentral.com, in a thread titled "Day 2 of the 800MHz patch." "Speed is incredible," posted another member, Bricktop.

But some others were reporting problems. "Day 1 was incredible, nothing bad can be said," posted Precentral member squeezy, with a Verizon-based Pre. "Today has been different. It started off when I was in headset mode talking on the phone, the screen would not come back on. So I held the power button down, it made the sound and vibrated, but still no screen. Not two hours later when on a call normal, I go to end it and the screen is unresponsive. Again I press the power button, sound, vibrate and screen notification come up, but the touch screen is not responsive. Both times I had to pull the battery. It has froze and locked up on its own just sitting there as well, each time resulting in a battery pull."

One member, Shadavis08, confirmed in a forum post that there are some similar reports "but im not sure that its related to the patch. what i would do is remove it and go down to the stock speed for a day and see if it still does that or drop down to the 720 kernel instead and see how that runs for you ok !"

Another user said his phone had begun randomly shutting down since he installed the kernel. He was going to remove it and "wait and see."

On Day 3 of the kernel "trial," there were similar mixed results. In some cases, users noted the phone heating up more than usual when doing sustained video downloads, for example (there's a Device Temperature Warning Patch available). The occasional random shutdown continued to be reported. One Precentral member, kevintranca, posted "i've been using my pre on 800 MHz and the battery life seems good until i actually make calls. making calls seem to totally drain my battery, does anyone else feel this way too? "