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RAID0: strange after effect- need help!

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July 13, 2011 11:35:25 AM

Hi everyone,
I have just enabled RAID0 with the JMicron RAID setup and the respective drivers. Everything works fine. HD Tune picks up the new RAID array as Main Disk, what I named it, and a size of 2000GB. And the speeds confirmed it was running properly. However, in 'My Computer', the hdd size is 1000GB and is named Partition 1. This is exactly how one of the drives was before I set up raid. Why is 'My Computer' not properly picking up the RAID array?
Thank you for any help!

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a c 415 G Storage
July 13, 2011 3:35:53 PM

If the disk was partitioned before you put it into the RAID-0 array then the system may be reading the old partition table and taking it as gospel. Go into Disk Management, delete the old partition and create a new one - that should fix the problem.
July 13, 2011 3:51:10 PM

Should I make the new partition a full 2TB size?
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a c 415 G Storage
July 13, 2011 7:45:36 PM

If you want to use all the space on the RAID volume then make it a 2TB partition.
July 13, 2011 10:50:24 PM

Hi,
I made the partition as large as I could- namely 1.8TB. There is 15gb of unallocated space which I cannot add into the large partition. Anyway, thanks for telling me how to do this :)  Is it normal that I do not notice a decrease in game loading times compared to before I setup RAID0 ?
a b G Storage
July 14, 2011 12:03:12 AM

You are most likely encountering the MBR limitation, you can convert the volume to GPT to access the rest of the space if this is not a boot volume. Yes you should notince a decrease in load times with RAID 0 since your throughput will essentially double.
a c 415 G Storage
July 14, 2011 1:16:38 AM

You'll only notice a difference for those programs that are actually on the RAID-0 volume, and then only if there are just a few program files that are fairly large. If there are a lot of smaller files that need to be loaded then RAID-0 won't show much of a performance increase (RAID-0 can improve transfer rates, but not access times).
July 14, 2011 7:16:56 AM

Hmm, all my files were on the one partition which I extended to use the full space of the two HDDs. But I notice no difference in startup time of Windows, application loading times and game loqading times. And tokencode, what is a MBR limitation? And yes, I use this drive as a boot drive. Also while recording, the fps goes even lower than before I had RAID0. I think the problem may be that Windows is only using one of the hard drives, because of the original partition?
In the benchmark, the access time is 16.4ms and average transfer speed is 149 mb/s
a b G Storage
July 14, 2011 7:47:22 AM

MBR limit is 2TB, but remeber that a k is really 1024 not 1,000 so this may show as 1.8TB

16.4ms random access is very high. If its a RAID 0 at the controller level, it couldn't possibly use a single disk.
July 14, 2011 7:50:05 AM

What do you mean with it couldnt possibly use a single disk if its raid0 at the controller level?
July 14, 2011 6:12:55 PM

olivierhacking said:
Hmm, all my files were on the one partition which I extended to use the full space of the two HDDs. But I notice no difference in startup time of Windows, application loading times and game loqading times. And tokencode, what is a MBR limitation? And yes, I use this drive as a boot drive. Also while recording, the fps goes even lower than before I had RAID0. I think the problem may be that Windows is only using one of the hard drives, because of the original partition?
In the benchmark, the access time is 16.4ms and average transfer speed is 149 mb/s


I'd say your main reason for seeing this is because you're using a JMicron RAID Controller and Software RAID with Windows. These JMicron controllers don't have the greatest performance for onboard RAID compared to Nvidia or Intel. If you truly want to see better performance from a RAID setup, use a Hardware RAID controller like Adaptec or LSI.
a c 415 G Storage
July 14, 2011 11:42:24 PM

olivierhacking said:
But I notice no difference in startup time of Windows, application loading times and game loqading times.
To significantly speed up those kinds of tasks you need a drive with faster access times, and RAID-0 will NOT give you that (nor will any other RAID organization). You may be able to measure the slight wall-clock improvement that RAID-0's faster transfer rates will give you, but chances are you won't notice it in practice.
a c 82 G Storage
July 16, 2011 4:08:00 AM

olivierhacking said:
What do you mean with it couldnt possibly use a single disk if its raid0 at the controller level?

After enabling RAID, did you create a 2 TB RAID 0 using both 1 TB hard disks and then reinstall Windows? If not, did you enable RAID on the controller and then expand the first disk to create a 1.8 TB partition? The speed would indicate that this is what you might have done.
a b G Storage
July 18, 2011 5:06:03 AM

What is the model of drive you are using for your RAID 0 set? 16.4ms access time is extrememly highly, 3 times higher than a good quality 7200rpm drive today. Are these 5400s?

sminlal, while its true RAID 0 doesn't decrease access times, it does increase throughput which will improve boot/game and application load times. I think the improvement in throughput would be a noticable improvement, depending on the type of reads being done (small number of large reads versus many smaller ones).


What I meant by that it couldn't be a single drive if the controller shows RAID 0 is that most controllers do not allow you to create a RAID 0 array from a single disk. Technically a single disk is RAID 0 with a single strip I guess, but normally this would be setup as a standalone disk not "RAID"

3xch4ng3 is also correct in stating that it could be an issue with your RAID controller. Have you checked for any firmware/driver updates? Have you tried the drives on another controller or another controller on the drives?
!