View Full Version : Data transfer rates - two internal drives

16-02-2012, 11:03 PM
Hi all

I have two internal drives on my system - C: is OD and apps, and D: is my data
When I set my system up a few years ago, I did it this was as a number of other people had, in order keep my data on a seperate physical drive, which is easier to backup, etc.

The problem is, I've been disappointed with how slow it often is when accessing data on Drive D (eg playing music and videos).
Recently I did a few comparisons. I played some video that were stored on C: drive, and it played smoothly, no stops or stuttering.
But the same videos, when played directly from D: drive, has regular skips and stuttering.
This is not streaming over a network or anything - this is simply playing directly on the same PC.

So the data transfer rate much be much slower from D: compared to from C:.
Now, I know my data drive is a WD Green, so it's more designed for power efficiency than performance - but still I expected to be able to access files faster. Even viewing a folder from it, such as my pictures or music folder, can take upwards of 30 seconds or more to display the contents.
Gaming performance is usually fine, but I assuming thats because the temp. game files are on C drive and not D drive.

I should mention my backup drive is a seperate, external drive plugged in via USB. I leave it plugged in and turned on always, but I run backups only about once a week. That drive being plugged in I assume should not affect the main drives speeds?

My question is, is this normal, and what troubleshooting can I do to try and improve this? (If any). It also does it for MP3s as well, so it's not just video files..it's quite frustrating actually.
Can I do any tests to see what the true data throughput rate from D drive is? And what speed should I expect it to be??
I should be able to play files directly from there without skipping, shouldnt I? Or am I expecting too much... (If I can't, why do so many other people also store their data on a seperate physical drive???)

I have all Windows up to date, and have scanned for viruses/malware etc.
I have checked my drivers are all up to date, too.
I have defragged the drives.

When Windows was installed, the drives were configured as AHCI - although I understand there should be little real world performance difference between this and IDE.

Thanks in advance...

My specs:
OS: Win 7 Home Premium 64 bit
CPU: Intel i7 860 2.80Ghz Quad Core
MB: Asus P7P55D Pro
GPU: ATI Radeon HD 4890
Monitor: Phillips 230C
HD1: C drive WD 1TD WD Black
HD2: D drive WD 1.5TB (data) WD Green
RAM: 6GB, Kingston

17-02-2012, 12:16 AM
Definitely something wrong there, I have a number of WD green drives and any Video plays smoothly including full HD blu ray rips.
Also in testing despite being the "slow" model they actually perform fairly quickly. They do seem to take a few seconds to wake up when I first access mine but after that it's fine.

The USB drive should not cause this, but it's not difficult to disconnect it for 5 mins and test so try that.
You could try a program like HDtach to benchmark your drives performance, sequential reads should be over 100MB/s I think.

I can't think what would cause this honestly, how full is the drive and is it connected to a SATA port on the motherboard or do you have a controller card?
You could try deleting the IDE / SATA controller from device manager, windows will reinstall it on reboot and that might help.

17-02-2012, 01:04 AM
Thanks for the reply.
I just downloaded HDtach now and ran a deep test on D drive. It shows average read speed of 45.9MB/s. Screenshot attached


How does this look? The first quarter of the test shows really slow speeds but after that it sped up to 80MB/s and then gradually slowed to about 25/30 as the test ended. With the avergae speed I guess maybe there were other processes accessing the drive that caused the slowdown - although I wasnt running any other intensive apps at the time of the test. Just Firefox and Outlook I think, but I wasn't actuall working with them as the test ran.

I will also try doing some tests with that other external drive unplugged to eliminate that as a cause.

The drive is not full - it has a capacity of 1.36TB and it has 410GB free, so plenty of spare space still.

I might also try your idea of deleting and reinstalling the controller. There is no risk of data loss by doing that is there??

Over the next few days I'll also look at the cables on the motherboard and double check it's connected to the correct port, I might have to find my MB manual first! (I dont really know what to look for to check that)...

17-02-2012, 10:09 AM
The first bit of the graph is terrible, perhaps the drive was in standby and had to wake up before it started working properly. Apart from that it's fairly typical except slower than I would expect. The random access 397ms just seems like its way too high but i don't know what would cause that.

Deleting the controller won't harm the contents of the disk.
Open task manager while you are testing and see what the CPU & memory usage looks like, I'm wondering if something else is going on in the background. Perhaps a hijack this log and a bribe to speedy could be a good Idea.

Other Ideas;
Try a different SATA cable, preferably a different length
Try a different SATA port on the motherboard, if they are coloured pick a different one as a test
Disable any Anti-virus or anti-malware temporarily to see if it's bogging things down (What AV are you using?)
Run a full scan with AV and antimalware software, MBAM, spybot, MSE, etc

Drive to drive transfers with a WD green drive are usually in the 40-50MB/s range on average, larger drives tend to be a bit faster due to higher data density. I'll try to remember to run HD tach on one of mine tonight for comparison, I have 2 WD green 2TB drives used for data and another 1TB one used as a system drive on another machine so maybe i can get a couple of results.

18-02-2012, 03:13 AM
Hi again

In device manager, I have the following listed under IDE ATA/ATAPI controllers

Which one(s) should I try to delete??

ATA channel 0 *
ATA channel 0 *
ATA channel 1 *
ATA channel 1 *
Intel(R) PCH SATA AHCI Controller
JMB36X Standard Dual Channel PCIE IDE Controller
Standard AHCI 1.0 Serial ATA Controller

* (Yep, these are both listed twice)

I'm a bit unsure about what does what, so I wanted to double-check before I delete something that I shouldn't...

As far as CPU / memory usage, these are fine whenever I have checked. Apart from the accosional spikes when I'm doing something, they stay low. For example right now (but I'm not doing much apart from browsing) CPU is 5% and used physical memory approx 50%.
I have already run fulls scans using MBAM and ESET, all is clear with those.

I will try the cabling checks over the weekend hopefully.

18-02-2012, 11:03 AM

2 different WD green drives on 2 different machines to compare.

It looks like you have two different onboard controllers, the intel one is part of the MB chipset and the Jmicron one is a seperate controller often used to add a couple of extra SATA and/or eSATA ports. Delete the bottom 3 entries but not all at once, delete one and reboot - see if it helps, if not try the next. I would definately try moving the port onto a different one on the motherboard, I found a few online forums where WD drives appear to have problems with particular chipsets.

Also the Jmicron could be adding IDE ports but if not then it's SATA and not in AHCI mode like the main controller is, could be worth looking in the BIOS to see if you can change it - perfectly safe as long as the C: drive isn't running on that controller and if it is you just have to change it back when it fails to boot. I mention this because IDE mode can sometimes have issues dropping to lower DMA settings or even into PIO mode. Right click on each ATA channel 1 at a time, chose properties, advanced settings, make sure they are all in UDMA mode, preferably mode 5 or 4, lower numbers perform worse and PIO mode is terrible.