# EXACT same HDDs same hdparm settings = diff performance?!!?!

## digitalsy

```
hdparm -i /dev/hda

/dev/hda:

 Model=WDC WD400BB-32BSA0, FwRev=12.08C12, SerialNo=WD-WMA741291192

 Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs FmtGapReq }

 RawCHS=16383/16/63, TrkSize=57600, SectSize=600, ECCbytes=40

 BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16

 CurCHS=4047/16/255, CurSects=16511760, LBA=yes, LBAsects=78165360

 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}

 PIO modes:  pio0 pio1 pio2 pio3 pio4 

 DMA modes:  mdma0 mdma1 mdma2 

 UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 

 AdvancedPM=no WriteCache=enabled

 Drive conforms to: device does not report version: 

 * signifies the current active mode
```

```
hdparm -i /dev/hdc

/dev/hdc:

 Model=WDC WD400BB-00DKA0, FwRev=77.07W77, SerialNo=WD-WMAHM1081371

 Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs FmtGapReq }

 RawCHS=16383/16/63, TrkSize=57600, SectSize=600, ECCbytes=74

 BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16

 CurCHS=65535/1/63, CurSects=4128705, LBA=yes, LBAsects=78165360

 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}

 PIO modes:  pio0 pio1 pio2 pio3 pio4 

 DMA modes:  mdma0 mdma1 mdma2 

 UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 

 AdvancedPM=no WriteCache=enabled

 Drive conforms to: device does not report version: 

 * signifies the current active mode
```

```
hdparm /dev/hda

/dev/hda:

 multcount    = 16 (on)

 IO_support   =  1 (32-bit)

 unmaskirq    =  1 (on)

 using_dma    =  1 (on)

 keepsettings =  0 (off)

 readonly     =  0 (off)

 readahead    = 256 (on)

 geometry     = 65535/16/63, sectors = 78165360, start = 0
```

```
hdparm /dev/hdc

dev/hdc:

 multcount    = 16 (on)

 IO_support   =  1 (32-bit)

 unmaskirq    =  1 (on)

 using_dma    =  1 (on)

 keepsettings =  0 (off)

 readonly     =  0 (off)

 readahead    = 256 (on)

 geometry     = 16383/255/63, sectors = 78165360, start = 0
```

ok and here's the hdparm -Tt test

```
hdparm -Tt /dev/hda

/dev/hda:

 Timing buffer-cache reads:   1100 MB in  2.00 seconds = 549.53 MB/sec

 Timing buffered disk reads:   72 MB in  3.05 seconds =  23.60 MB/sec
```

```
hdparm -Tt /dev/hdc

/dev/hdc:

 Timing buffer-cache reads:   1080 MB in  2.01 seconds = 537.93 MB/sec

 Timing buffered disk reads:  120 MB in  3.01 seconds =  39.90 MB/sec
```

These are both 7200rpm WD WD400BB hard drives (40GB) Why is one faster than the other with the EXACT same settings?!

Please assist it's slowing down my raid device which is a raid0 of both of these. it can only go so fast as the slowest disk, so i'm losing speed!

-digi[/code]

----------

## pjp

Have you tried testing the drives independently, with only one drive on the controller at a time?

Moved from Other Things Gentoo.

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## digitalsy

Each drive is on a seperate controller already, hda and hdc....

----------

## digitalsy

NOTE* It should be noted this is on a desktop not a laptop. Please move to appropriate forum if required* 

thanks

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## pjp

 *digitalsy wrote:*   

> Each drive is on a seperate controller already, hda and hdc....

 Ah, missed that.

Hardware AND Laptops.  (I never cared for the Laptop part)

----------

## digitalsy

I'm so baffled...I do not understand how 2 identical drives (although with different geometries) can have a 10MB/s speed difference...makes no sense...

----------

## digitalsy

Does disk geometry have anything to do with performance? that is the ONLY thing that differs between these 2 drives, otherwise they are indentical

digi

----------

## Regor

Judging from the model names and firmware revs it looks like they are slightly different drives. I don't know WD's manufacturing process, but there could be small differences in the hardware between the two drives. Even more suspicious is the wide variance in firmware levels. The ECC byte count differs too though I couldn't guess at the significance of that.

All told, though, it's the sort of thing that could easily cause a small but significant performance variation between two drives that are otherwise of the same model. I would suspect the drives until given a chance to test two of identical specs.

----------

## sindre

Do you have a cdrom on the same controllar as the slower hd? This might degrade performance by a good deal.

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## digitalsy

No both these drives are master on their own ide controller hda and hdc there exists no hdb or hdd on my system....

----------

## blueworm

Dont waste time harddisk warranty period is now only 1 year.

This is not nornal...

Return the disk.

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## digitalsy

The hard disk works fine, no bad sectors - nothing really wrong except this performance issue...are you sure this could be a defect?

----------

## Moofed

You could use the S.M.A.R.T. feature of harddrives and find out even more info using smartmontools.  For the lazy:

```
emerge smartmontools

/etc/init.d/smartd start

smartctl -t short /dev/hda

smartctl -a /dev/hda
```

Here is the output from my 60GB Seagate:

```
lewis smartmontools-5.23 # smartctl -t short /dev/hda

smartctl version 5.23 Copyright (C) 2002-3 Bruce Allen

Home page is http://smartmontools.sourceforge.net/

=== START OF OFFLINE IMMEDIATE AND SELF-TEST SECTION ===

Sending command: "Execute SMART Short self-test routine immediately in off-line mode".

Drive command "Execute SMART Short self-test routine immediately in off-line mode" successful.

Testing has begun.

Please wait 1 minutes for test to complete.

Test will complete after Thu Nov  6 09:28:50 2003

Use smartctl -X to abort test.

lewis smartmontools-5.23 # smartctl -a /dev/hda

smartctl version 5.23 Copyright (C) 2002-3 Bruce Allen

Home page is http://smartmontools.sourceforge.net/

=== START OF INFORMATION SECTION ===

Device Model:     ST360021A

Serial Number:    3HR0W1CW

Firmware Version: 3.19

Device is:        Not in smartctl database [for details use: -P showall]

ATA Version is:   5

ATA Standard is:  Exact ATA specification draft version not indicated

Local Time is:    Thu Nov  6 09:29:05 2003 EST

SMART support is: Available - device has SMART capability.

SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===

SMART overall-health self-assessment test result: PASSED

General SMART Values:

Offline data collection status:  (0x82) Offline data collection activity was

                                        completed without error.

                                        Auto Offline Data Collection: Enabled.

Self-test execution status:      (   0) The previous self-test routine completed

                                        without error or no self-test has ever 

                                        been run.

Total time to complete Offline 

data collection:                 ( 422) seconds.

Offline data collection

capabilities:                    (0x1b) SMART execute Offline immediate.

                                        Auto Offline data collection on/off support.

                                        Suspend Offline collection upon new

                                        command.

                                        Offline surface scan supported.

                                        Self-test supported.

                                        No Conveyance Self-test supported.

                                        No Selective Self-test supported.

SMART capabilities:            (0x0003) Saves SMART data before entering

                                        power-saving mode.

                                        Supports SMART auto save timer.

Error logging capability:        (0x01) Error logging supported.

                                        No General Purpose Logging support.

Short self-test routine 

recommended polling time:        (   1) minutes.

Extended self-test routine

recommended polling time:        (  44) minutes.

SMART Attributes Data Structure revision number: 10

Vendor Specific SMART Attributes with Thresholds:

ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE

  1 Raw_Read_Error_Rate     0x000f   070   061   034    Pre-fail  Always       -       48574718

  3 Spin_Up_Time            0x0003   070   070   000    Pre-fail  Always       -       0

  4 Start_Stop_Count        0x0032   100   100   020    Old_age   Always       -       49

  5 Reallocated_Sector_Ct   0x0033   100   100   036    Pre-fail  Always       -       0

  7 Seek_Error_Rate         0x000f   078   060   030    Pre-fail  Always       -       8715523278

  9 Power_On_Hours          0x0032   094   094   000    Old_age   Always       -       5342

 10 Spin_Retry_Count        0x0013   100   100   097    Pre-fail  Always       -       0

 12 Power_Cycle_Count       0x0032   100   100   020    Old_age   Always       -       465

194 Temperature_Celsius     0x0022   040   054   000    Old_age   Always       -       40

195 Hardware_ECC_Recovered  0x001a   070   061   000    Old_age   Always       -       48574718

197 Current_Pending_Sector  0x0012   100   100   000    Old_age   Always       -       0

198 Offline_Uncorrectable   0x0010   100   100   000    Old_age   Offline      -       0

199 UDMA_CRC_Error_Count    0x003e   200   200   000    Old_age   Always       -       0

200 Multi_Zone_Error_Rate   0x0000   100   253   000    Old_age   Offline      -       0

202 TA_Increase_Count       0x0032   100   253   000    Old_age   Always       -       0

SMART Error Log Version: 1

No Errors Logged

SMART Self-test log structure revision number 1

Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error

# 1  Short offline       Completed without error       00%      5342         -

# 2  Short offline       Completed without error       00%      5333         -

```

----------

## Kabuto

Couple of notes:

1) Firmware revision.  There could have been improvements in IDE handeling.

2) hdparm - CurSects  Much smaller on the new drive 4M vs 16M.  Could this be something?

----------

## Kabuto

Ah.  A couple of searches on StorageReview.com and found out that your new drive uses a 40GB platter vs a 30GB? platter.  Denser=faster.  They also might use newer motor drives that are supposed to be quieter.  Notice it any?

3 Digit on extended model # (ex 32B.. vs 00D)

A = 20GB platter(s)

B = 30GB? platter(s)

C = 40GB platter(s)

D = 60GB platter(s)

E = 80GB platter(s)

F = 80GB platter(s) w/FDB

----------

## digitalsy

How can a 40GB hard drive have a 60GB platter?

----------

## Malakin

 *Quote:*   

> How can a 40GB hard drive have a 60GB platter?

 By only using 40GB of it :) This is common as it is sometimes more expensive for the manufacturer to make several different platters then it would be to just make one and only use part of the platter sometimes.

I suppose it's also possible that a 40GB drive using a 60GB platter could be using a platter where some of the surface didn't pass their testing so only a portion of it's used (just speculating though).

----------

## Kabuto

Actually sorry, brain fart.  WD admits a 40GB platter in D series.  The chart is wrong.  Earlier 400BB used 2x20GB platters that WD doesn't use anymore.  So basically 1 denser platter makes it faster than two smaller.

----------

## Kabuto

FYI.  The best way to tell is throughput testing.  I have a 80GB and get ~37MB/s on hdparm so I have 2x40GB platters.  HDTach is better than hdparm for testing as it give high and low for the drive. WD has 40, 60, 66, and 80GB platters now.  Supposedly new 400JB have the 80GB platters. A 60GB platter drive should get ~42MB/s on hdparm.  I guess hdparm give a middle platter reading so you get an average speed.  For example 40GB platters go ~29-49MB/s 60GB 32-54MB/s.

But anyway   :Laughing:    Have fun with your faster drive.

----------

## digitalsy

So basically my problem isn't really a *problem* it's because I have one model of drive which is a 40gb platter and performs slower, whereas the newer version with the 60GB platter gets better performance?

----------

## Kabuto

Yes.  But I think the chart I posted doesn't work with the 400BB.  I think your old had 2x20GB platters and the new has 1x40GB platter so it is faster.  The media is "denser" so in one revolution the head picks up more information than the old drive.

----------

## digitalsy

Took my new 40gb back and paid 6$ more to get an 80gb 8mb 7200rpm wd, and bought a 2nd one also. Will post results when gentoo is installed...

----------

## Kabuto

Hah.  Good buy.  This all reminds me of a long time ago when Seagate had their ST251 40MB HD.  You could get a Singapore made version that had a 40ms access time vs. the other which had an 80ms access time.  Both the same model #.

----------

## digitalsy

Well I'm bootstrapping now (stage1) but i managed to test each drive individually with hdparm in the livecd. Each identical drive got 53MB/s and the array once created got 106MB/s. Wooohoo, some real performance now  :Smile: 

-digi

----------

## wulu

it coul be the motherboard, maybe the second ide controller

isn't that fast - you could try to switch the disks and boot the 

livecd for another test

----------

