Since I already upgraded (downgraded?) the laptop to Windows 8 (fresh install) and didn't capture benchmark screenshots at the time, I ran PerformanceTest v7.0 on an identical laptop running Vista Business for comparison. Though there is a different hard drive on this Dell E6500 Vista laptop, which did score slower in the hard drive benchmark testing than the Windows 8 Dell E6500. You would think a slower hard drive, a major factor in system performance would cause the Vista Business laptop to be slower than the Windows 8 laptop. Yeah, well we'd both be wrong. The overall PassMark score for the Vista laptop was 611.6 while the Windows 8 PassMark score was 411.7. Mind you, the Vista laptop would have scored even higher, had not the slower hard drive affected its score.
Let's go to the video tape and compare each laptop's benchmarks by category:
Vista System:
Windows 8 System:
Look at the red arrow above and compare with the prior image. You'll see that Windows Vista is using a 9X multiplier with a measured speed of 2261.1Mhz while Windows 8 is using a 6X multiplier with a measured speed of 1596.0Mhz. Well, there's the problem right there. For whatever reason, Windows 8 is underclocking the CPU - though I may be misusing that term. Interestingly, the Windows 8 laptop has a slightly faster Bus Speed and Front Side Bus, but not enough to make up for the fact that the CPU multiplier is only 6X.
Let's look at how this affects the other scores, including the 2D & 3D graphics score, memory score, etc.
Vista Summary:
Windows 8 Summary:
Vista CPU Mark:
Windows 8 CPU Mark:
Vista 2D Graphics Mark:
Windows 8 2D Graphics Mark:
Vista 3D Graphics Mark:
Windows 8 3D Graphics Mark:
Vista Memory Mark:
Windows 8 Memory Mark:
Vista Disk Mark: [only category where Vista scored lower due to different HDD]
Windows 8 Disk Mark:
Lastly, I wanted to show a screenshot of the Device Manager demonstrating that Windows 8 properly detected the dual core processor and there are no yellow exclamation marks under System Devices:
Conclusion:
Obviously, this is 'preview version' of Windows 8 (not even a beta yet) intended for developers and bleeding edge users - and not intended for production environments. Still, I wouldn't expect Windows 8 to not use the proper multiplier (9X) for the CPU clock speed. I upgraded the BIOS on the laptop, but that didn't help. I also tried turning off Intel SpeedStep to no avail. I also tried modifying my Power Plan to High Performance, thinking maybe the "Balanced" power plan was limiting the CPU clock speed. That didn't work either. I'm sure Windows 8 will work great on new hardware when it's released, but I for one will be hesitant to upgrade any computers/laptops because of the risk of a huge performance hit. Hopefully, Microsoft will fix the problem and advertise the fact that the CPU slowness issue was simply due to a driver issue or something else that is readily resolved.
Update:
Just ran the popular CPU-Z utility. According to CPU-Z, the Windows 8 laptop doesn't detect any multiplier and is running the clock speed at 1358.7MHz, while Vista's multiplier was usually 9X (though screenshot shows 8.5X) at a clock speed of 2261.1MHz. Definitely a problem with Windows 8's detection of processors and their capabilities.
Vista:
Windows 8:
Update 2:
I just realized that disabling Intel SpeedStep in the BIOS does improve performance, though it still doesn't match Vista's benchmark numbers. Still, it is much better now that I've disabled it. The prior screenshots were all taken with Intel SpeedStep DISABLED (faster). However, it is preferable to have this feature turned on. When I did have it enabled, performance was much worse. Here's 3 more screenshots showing Windows 8 performance with Intel SpeedStep ENABLED. If you compare with screenshots above you'll see a drastic performance drop with Intel SpeedStep turned on in the BIOS.
Windows 8 Summary: [e.g. PassMark drops from 411.7 to 243.7]
Windows 8 CPU Mark:
Windows 8 Memory Mark:
