I had a lot of trouble with the SATA IDE vs. AHCI issue I described in one of the earlier posts. I got the Windows 8 install done with SATA set to IDE mode in the BIOS, but I wanted to see if there was any way to switch it back to AHCI. I was hopeful that whatever bug prevented it from working in Windows 8 was fixed in 8.1, or in one of the many Windows updates that came down post-install.
Well, first, I found out that, once you’ve installed Windows 8 with the BIOS set to IDE mode, you can’t just switch it back, since Windows doesn’t detect the change automatically. So doing that just results in a boot failure. This blog post describes a way to deal with that; basically, boot into safe mode right after changing the BIOS and Windows will reconfigure itself. But, in my case, that didn’t help.
I also noticed that an optional update for NVIDIA SATA controller was available from Windows Update. I was hopeful that it would fix the problem, but installing that update causes Windows to crash on boot, so that’s no good either. I had to use system restore to remove that update and boot into Windows again. (Oh, and getting to system restore in Windows 8.1 is a bit of a challenge, but that’s another story.) I have a feeling that, maybe, some magic combination of installing that update, booting into safe mode, and switching back to AHCI mode might work, but I’m not sure it’s worth the effort. If I feel adventurous at some point, I might try the SATA driver found here. But I’ll want to make sure I have a restore point, a full backup, and ample spare time before messing with that.
I’m not sure how much of a performance penalty there is in running in IDE mode rather than AHCI. I searched for some info on that, but didn’t find anything definitive. The main performance advantage with AHCI would be related to Native Command Queuing (NCQ), which would increase performance on some drives in some scenarios. In my case, I’m not sure if it would be enough of a difference to bother with.
Regardless of all that, the machine seems much faster now than it did before all this. I imagine most of the performance bump is just due to the clean install, but some of it may be from Windows 8.1 being a bit faster than Windows 7 in some ways. So I’m mostly satisfied that all this work wasn’t for naught.
Oh, and just for yuks, I decided to run the Windows System Assessment Tool on the desktop PC, and on my ThinkPad, to see what the performance difference is between the new SSD in the ThinkPad vs. the old-fashioned drive in the desktop. And it’s a doozy!
Using the command “winsat disk -drive c”, I got the following numbers on the desktop:
> Run Time 00:00:15.75 > Disk Random 16.0 Read 0.86 MB/s 2.9 > Disk Sequential 64.0 Read 84.51 MB/s 6.3 > Disk Sequential 64.0 Write 68.13 MB/s 5.9 > Average Read Time with Sequential Writes 6.986 ms 5.3 > Latency: 95th Percentile 121.125 ms 1.9 > Latency: Maximum 475.244 ms 3.7 > Average Read Time with Random Writes 13.882 ms 3.6 > Total Run Time 00:01:07.41
And here are the numbers on the laptop:
> Run Time 00:00:00.63 > Disk Random 16.0 Read 411.49 MB/s 8.2 > Disk Sequential 64.0 Read 524.08 MB/s 8.1 > Disk Sequential 64.0 Write 375.03 MB/s 8.0 > Average Read Time with Sequential Writes 0.121 ms 8.8 > Latency: 95th Percentile 0.302 ms 8.8 > Latency: Maximum 0.981 ms 8.9 > Average Read Time with Random Writes 0.112 ms 8.9 > Total Run Time 00:00:06.86
So, yeah, that’s a big difference!
My big takeaway from all this messing around is that my desktop PC is definitely near the end of it’s useful life. I’m not going to want to upgrade it again, past Windows 8.1. So I think I’ll keep using it as-is for the foreseeable future, then, maybe in a year or so, consider a new machine. Maybe when Windows 10 comes out.
For the past 20 years or so, I’ve always had a Windows box at home as my main desktop computer, generally in a mid-tower case sitting on the floor next to my desk. But I’m starting to rethink that. Depending on what happens with Windows 10, and what happens in my professional life, I may switch over to a Mac Mini as my desktop machine, and just keep a Windows laptop for the stuff I really need Windows for. I’m definitely using my MacBook a lot more often than either my ThinkPad or desktop PC at this point. But I don’t really need to make a decision on that yet.