Original URL: http://www.theregister.co.uk/2008/04/14/review_penryn_t9500/

Intel Core 2 Duo T9500 mobile 'Penryn' processor

Rock updates its X770 laptop with the latest mainstream mobile CPU

By Leo Waldock

Posted in Hardware, 14th April 2008 11:02 GMT

Review We started the year with a review of a Rock X770 gaming laptop. We used the machine to look at the Nvidia GeForce 8800M GTX graphics chip, but it's time to look at the processor, now upgraded to Intel's 45nm mobile Core 2 Duo T9500.

Rock Xtreme X770 notebook

Rock's Xtreme X770: now with Penryn

The X770 we looked at before came with a 2.6GHz, 65nm Core 2 Duo T7800, which contained 4MB of L2 cache and sat on an 800MHz frontside bus (FSB). The T9500 runs at the same clock speed as the T7800 and the same FSB frequency, but it packs in an extra 2MB of L2.

Looking deeper into the specifications of the two processors, the TDP remains unchanged between the generations - both consume up to 35W. However, the core voltage drops from 1.363V on the T7800 to 1.063V with the T9500. The other change is in the instruction set, as the old 65nm 'Merom' core supports SSE 3, while the 45nm 'Penryn' core supports SSE 4.1. But that’s not currently of much use unless you are running the latest version of DivX.

Rock sent us the X700 laptop with both T7800 and T9500 CPUs. The machine also had GeForce 7950 Go GTX graphics installed, as had one of the two X770s we looked before, so the new model is directly comparable with the version that we saw in our previous review.

Rock X770 - inside

Remove the battery and behold: the beast's innards

Swapping the processors was incredibly simple. Remove the battery, unscrew the bottom plastic cover and then undo the three screws that hold the heatsink against the processor. Swap processors, replace the heatsink, cover and battery, and you’re done. The Bios handles the changes without any input from the user.

In a straight head-to-head in PCMark05 there was nothing to choose between the two processors, which is much as you'd expect. The Penryn processor has only a tiny advantage in this benchmark as it is a couple of years old and doesn’t use SSE 4. It was a similar story in 3DMark06 which is, of course, a graphics test. The overall score was the same for both processors, although the CPU element was very slightly better for the Penryn.

PCMark05 Results

Intel Core 2 Duo T9500 - PCMark05 Results

Longer bars are better

3DMark06 Results

Intel Core 2 Duo T9500 - 3DMark06 Results

Longer bars are better

The POV-Ray graphics rendering test showed Penryn in a better light as the new core is more efficient than Merom, but it’s unlikely that many people will use their Rock laptop to render pro graphics.

POV-Ray 3.7 Beta 25 Results

Intel Core 2 Duo T9500 - POV-Ray Results

Time in Seconds
Shorter bars are better

These three tests show the highest increase in performance you're going to get in games, which are typically limited more by the GPU than the CPU. So, yes, you'll get a higher framerate with the T9500 than the T7800, but not a significantly higher one.

For our battery test we ran continuous loops of PCMark05 and expected that Penryn would have a small advantage so it came as a real surprise to see battery life increase from 56 minutes with the T7800 to one hour seven minutes with the T9500. That’s about 20 per cent which is simply startling for nothing more than a processor change.

Battery Life Results

Intel Core 2 Duo T9500 - Battery Life Results

Battery run-time in Minutes
Longer bars are better

As a rule of thumb you should double those battery life figures to get an estimated real-world figure as we hammered the battery without mercy during the run-down.

It was noticeable that the CPU cooling fan would operate in fits and starts even when the laptop was under a light load, running just the Windows desktop. It seemed that the fan ran less often with the T9500 than with the T7800, and while that’s a personal judgement the noise of the Rock was less annoying with the Penryn installed.

Rock Xtreme X770-T7800 notebook

Better battery life with Penryn than with Merom

Best of all we cannot see a downside to mobile Penryn. It’s all good news.

Verdict

Mobile Penryn may seem like a minor update to Merom and, indeed, the increase in performance the new 45nm part offers is small. However, Penryn delivers a very welcome boost to battery life.