I give up

So concluded on how to get partitions aligned on 4k boundaries (WDC WD15EARS-00Z), for ~60 MB/s. But if I add a ext3 FS on top, speed drops to 20 MB/s. With LVM or without.

fdisk -u -l /dev/sdb 

Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes
224 heads, 56 sectors/track, 233599 cylinders, total 2930277168 sectors
Units = sectors of 1 * 512 = 512 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1              56     1593087      796516   83  Linux
/dev/sdb2         1593088  2930265855  1464336384   8e  Linux LVM

pvcreate -M2 --dataalignment 256K --zero y /dev/sdb2
vgcreate VolGroup00 /dev/sdb2
lvcreate --size 1429007m -n LogVol00 VolGroup00
lvcreate --size 512m -n LogVol01 VolGroup00

mkfs -t ext3 -E stride=64,resize=1500G /dev/mapper/VolGroup00-LogVol00
time dd if=/dev/zero of=/mnt/10gb bs=1024k count=10240
10240+0 records in
10240+0 records out
10737418240 bytes (11 GB) copied, 581.433 seconds, 18.5 MB/s

real    9m41.976s
user    0m0.120s
sys     5m42.148s

Even without LVM

lvremove /dev/VolGroup00/LogVol01
lvremove /dev/VolGroup00/LogVol00
vgremove
pvremove /dev/sdb2
time mkfs -t ext3 -E stride=64,resize=1500G /dev/sdb2

real    9m45.448s
user    0m1.370s 
sys     4m3.243s 

mount -o noatime /dev/sdb2 /mnt
time dd if=/dev/zero of=/mnt/10gb bs=1024k count=10240 ; rm
-fv /mnt/10gb 10240+0 records in
10240+0 records out
10737418240 bytes (11 GB) copied, 531.348 seconds, 20.2 MB/s

For comparison, here's the same 10 GB creation on a 750 GB Seagate (ST3750330AS), plugged into the same computer. Yes, this is 7200 RPM vs 5400 RPM, but that should mean half the speed!

time dd if=/dev/zero of=/tmp/10gb bs=1024k count=10240 ;
10240+0 records in
10240+0 records out
10737418240 bytes (11 GB) copied, 278.679 seconds, 38.5 MB/s

real    4m38.790s
user    0m0.090s
sys     1m47.174s

Only way to get sane speed is with ext4.

time mkfs -t ext4 -E resize=1500G /dev/sdb2
real    8m5.862s
user    0m3.230s
sys     3m13.791s

mount -o noatime /dev/sdb2 /mnt
time dd if=/dev/zero of=/mnt/10gb bs=1024k count=10240 
10240+0 records in
10240+0 records out
10737418240 bytes (11 GB) copied, 324.92 seconds, 33.0 MB/s

real    5m24.987s
user    0m0.140s 
sys     2m10.760s

So basically, I gave up. And ordered an SSD instead. X25-V 40gb go for a bit over 100 bux. What's more, the WD Green had an annoyingly clicky head.