13.4 ms Random Access Time on Maxtor 7200 rpm 40gb drive???

[salman327]

I thought these were suppossed to have an access time of 8.5 ms or so. Am I looking at the right time, or is some fluctuation suppossed to happen? I used Hd Tach to figure out the RAT

 

[CQuinn]

What model?

 

[Rand]

No IDE HDD on the face of the earth has ever has a Sub 11ms access time, and you can bet there isnt any IDE drives that can come even remotely close to 8.5ms irregardless of model or brand.

Are you sure your not confusing seek time with access time?
They are two different numbers.
The Maxtor D740X series has a specified 8.5ms seek time if I recall correctly, I can't remember the specified access time but it is not even theoretically possible for a 7200RPM IDE HDD to have an access time on 8.5ms.

Also, remember to enable "advanced size check" to get a proper reading, otherwise HDTach will only measure across the first 8GB rather then the entire disk.

 

[RatDog8102]

How does one enable the ASC? I have seen others mention this setting but I can't find it. I am using unregistered HD tach version 252.

 

[Rand]

<< How does one enable the ASC? I have seen others mention this setting but I can't find it. I am using unregistered HD tach version 252. >>



As soon as you start the proggy ASC is directly to the right of "Enable Write Test". Just check the ASC box and it's enabled.
I'm using 2.61 registered, but if I recall correctly it's the same it 2.5X unregistered.

 

[RSI]

<< No IDE HDD on the face of the earth has ever has a Sub 11ms access time, and you can bet there isnt any IDE drives that can come even remotely close to 8.5ms irregardless of model or brand.

Are you sure your not confusing seek time with access time?
They are two different numbers.
The Maxtor D740X series has a specified 8.5ms seek time if I recall correctly, I can't remember the specified access time but it is not even theoretically possible for a 7200RPM IDE HDD to have an access time on 8.5ms.

Also, remember to enable "advanced size check" to get a proper reading, otherwise HDTach will only measure across the first 8GB rather then the entire disk. >>

Two things. First is that you're wrong about no drive on the earth being able to get lower than 11. Secondly is, irregardless - all I have to say about that is : ROFTLMAO!

Anyways, yes, sub-11 time is possible and feasible. My older Quantum drive has gotten that - using HD Tach under Win9X, about 8 months ago. When I moved to Win2K, I noticed my seek time went up to 10-11ms. This bothered me a bit, but I lived with it, since Win2K provided so many improvements over Win9x.

And another thing, about HD Tach. Checking "advanced size check" does nothing for me. It tests the whole drive regardless of me clicking the checkbox, on both my 20GB 7200rpm Quantum drive and my 40GB 7200rpm Maxtor drive. The Maxtor drive is funky right now, and is getting 19(lowest so far) to 30 (highest) milliseconds time. My Quantum rests at approximately 11 as usual, in Win2K Pro. I'd load up Win9x again to take a pic to prove it, but it's not worth the hassle to prove to some anonymous GH surfers that my HD can do it, plus my drive is NTFS so I'd really have to total everything.

Point is, for a new hard drive, yes, 13.4ms is a little high... for a 7200rpm Maxtor. It should get closer to 8.5 - 10ms, but 13 is still alright, you can definitely live with that. It's not like the Maxtor I have downstairs right now. Be happy yours is that good. 😉

-RSI

 

[Accord99]

8.something ms is the rated seek time, however to get the rated access time, you add 4.17ms for a 7200rpm drive. So your score is a bit higher than expected but not far off.

The fastest EIDE hard drive ever in terms of access time is the Quantum PLus LM which was around 11.5ms.

 

[RSI]

<< 8.something ms is the rated seek time, however to get the rated access time, you add 4.17ms for a 7200rpm drive. So your score is a bit higher than expected but not far off.

The fastest EIDE hard drive ever in terms of access time is the Quantum PLus LM which was around 11.5ms. >>

That's the drive I have in this computer. I am getting 11ms and like I said i've seen 8-9ms. If what you're saying is true, how is it physically possible that I got those scores?

-RSI

 

[RatDog8102]

OK, I downloaded HDTach 2.61 and it has ASC where 2.52 did not. With ASC checked I get a RAT of 14.5ms and Read Speed average of 19859kps. With ASC unchecked I get 10.6 and 22550 respectively. So obviously ASC does make a difference.

 

[John]

<< The fastest EIDE hard drive ever in terms of access time is the Quantum PLus LM which was around 11.5ms. >>

That's the drive I have in this computer. I am getting 11ms and like I said i've seen 8-9ms. If what you're saying is true, how is it physically possible that I got those scores?

-RSI[/i] >>



8-9ms access time for an IDE drive? No. As far as your 11ms score, it sounds like a glitch to me.

 

[Accord99]

<< That's the drive I have in this computer. I am getting 11ms and like I said i've seen 8-9ms. If what you're saying is true, how is it physically possible that I got those scores?

-RSI >>



You only tested the first 8GB of the drive, which results in the lower access times. 11.5ms is for the entire drive, which can be tested using HDtach 2.6 and checking Advanced Size Check for Win9x (it automatically checks the entire drive in Windows 2000/XP) or using Winbench.

 

[Doomguy]

The score HDTach gives includes the rotational latency. See StorageReview . Read any hard drive review and you'll see they subtract the rotational latency from the reported seek time.

All of the scores you guys posted are fine.

 

[Pariah]

"First is that you're wrong about no drive on the earth being able to get lower than 11."

He said no IDE drive, and he is right. On the flip side, the only currently produced SCSI drive that tests slower than 11ms access is the 7200RPM 12 platter 180GB Seagate Barracuda 180, which at 12.1 is still in the upper echelon of IDE drives (actually faster than any currently produced IDE drive).

"Anyways, yes, sub-11 time is possible and feasible. My older Quantum drive has gotten that - using HD Tach under Win9X, about 8 months ago. When I moved to Win2K, I noticed my seek time went up to 10-11ms. This bothered me a bit, but I lived with it, since Win2K provided so many improvements over Win9x."

The fastest IDE drives ever in access were the Quantum fireball+ series, all except the AS+ test in the mid 11's, nothing below 11.4. I owned a KA+ and a LM+ and they never tested below 11.4. Also, OS does not affect access time, maybe a negligible .1ms, certainly not 1ms.

"It tests the whole drive regardless of me clicking the checkbox"

If you're using a Windows NT variant, it won't do anything, if you are using a Win9x variant, you do have to check it.

"It should get closer to 8.5 - 10ms, but 13 is still alright, you can definitely live with that."

No, it shouldn't. The last few Maxtor drives are testing in the low 12's which is very good for an IDE drive. There is no way any 7200 RPM drive is getting 8.5ms. Subtracting the average latency for a 7200RPM drive of 4.2ms would give you seek times of around 4 which is absurdly fast territory that only the current generation 15k RPM SCSI drives hit, and that is with the assistance of much smaller diameter platters (2.6in vs ide 3.5in).

 

[salman327]

Oh I must've confused the times then. I've always felt this hd was little slow, considering the fact that I moved up from a 5400 IBM drive. Maybe the spead increase isn't as noticable, and is only noticable w/ certain software.

 

[salman327]

I think he meant add the 4.2 extra ms to the seek time, I think. Thanks for your help guys

 

[Rand]

<< Two things. First is that you're wrong about no drive on the earth being able to get lower than 11. Secondly is, irregardless - all I have to say about that is : ROFTLMAO! >>



I did not say no drive can do it, I said no IDE drive on the planet that has yet been manufacturerd and mass produced can do it.



<< That's the drive I have in this computer. I am getting 11ms and like I said i've seen 8-9ms. If what you're saying is true, how is it physically possible that I got those scores? >>



It is not possible. If your IDE HDD has an access time of under 11ms across the whole disk then it has broken the laws of physics. It's is guaranteed not possible for any currently available 7200 RPM IDE HDD to break 11ms access time. Anything saying otherwise is either incorrectly measuring access time, or is not measuring across the entire disk.



<< And another thing, about HD Tach. Checking "advanced size check" does nothing for me. It tests the whole drive regardless of me clicking the checkbox, on both my 20GB 7200rpm Quantum drive and my 40GB 7200rpm Maxtor drive. >>



Advanced Size Checking is autmoatically enabled under the NT kernel, and it ignores the user applied setting. Re-test under Win9X and you will see it test only the first 8GB of the drive. The HDTach documentation from TCD Labs confirms this.



<< Point is, for a new hard drive, yes, 13.4ms is a little high... for a 7200rpm Maxtor. It should get closer to 8.5 - 10ms, but 13 is still alright >>



Please explain to me how you figure this.

Access Time = Command Overhead Time + Seek Time + Settle Time + Latency

Maxtor's specs for the D740X
Maxtor specifically states a specified average seek time of 8.5ms.

The latency period for a 7200RPM drive across the entire disk is 4.2ms as is confirmed in Maxtor's specifications.

Let us assume both the drive and the IDE interface operate at the speed of light and therefore there is absolutely no command overhead time, and no settle time at all.

Therefore we have a total of 12.7ms access time at the lowest the drive can possibly record across the entire disk.

Now let us assume Maxtor is lying to us and the drive does in actuality operate at 10,000RPM... the latency period of a 10,000 RPM HDD is 3ms.
We would then end up with a total of 11.5ms access time. This is still above the 11ms access time I mentioned as being impossible for the drive to break. And even after this we are still ignoring the impact of command overhead time and settle time which would further increase this figure slightly, albeit by a very minor amount indeed.

If you wish you can confirm everything I've said on the TCD Labs website, the marks of HDTach.
I really don't know how else to better explain this.
If you wish I can point you to many many artciles discussing how access time is calculated with an in-depth discussion of the theoretical capabilities of a 7200RPM IDE HDD and other IDE/SCSI variants.

 

[Pariah]

"It is not possible. If your IDE HDD has an access time of under 11ms across the whole disk then it has broken the laws of physics. It's is guaranteed not possible for any currently available 7200 RPM IDE HDD to break 11ms access time. Anything saying otherwise is either incorrectly measuring access time, or is not measuring across the entire disk."

Maybe I'm misunderstanding what you are saying here. Are you implying that no 7200RPM drive can ever have an average access time below 11ms, or that no IDE drive that is already on the market can't? A 7200 RPM IDE drive can certainly be built that will have a lower average access time than 11ms. It just hasn't been built yet. You do say currently available, but seem to imply otherwise.

"Therefore we have a total of 12.7ms access time at the lowest the drive can possibly record across the entire disk."

I'm not sure how you came up with this. 12.7ms is the average access time, so in actuality it isn't across the entire disk, only half of it. In order to calculate the lowest access time across the entire disk you have to use the full stroke seek time, and assume 0 latency (the platter doesn't have to rotate any to find data). Maxtor doesn't give full stroke stats, but Quantum does. For the AS+, the average seek is 8.5ms, the full stroke is 17ms. So the fastest possible disk access across the whole disk surface is 17ms. The worst case possible would be full stroke seek plus full rotational latency (4.2 is an average{full spin / 2}) which would result in an access time of 23.2ms for an AS+. Any drive regardless of specs can achieve a 0ms access time not including overhead, if the data is under the head at the exact time the data is requested.

Take manufacturers' stated stats with a grain of salt. Usually the claimed average seek is lower than the actual, though occasionally a drive will test lower than claimed. Latency doesn't really need to be stated, since it is determined by the rotational speed. A 7200RPM drive can only have an average latency of 4.2ms, no higher no lower, unless time and space are warped.