All Posts by Date or last 15, 30, 90 or 180 days.
also by Lloyd: diglloyd.com photography and WindInMyFace.com

Thank you for buying via links and ads on this site,
which earn me advertising fees or commissions.
As an Amazon Associate I earn from qualifying purchases.

Other World Computing...
B&H Photo...
Amazon
As an Amazon Associate I earn from qualifying purchases.
Upgrade the memory of your 2020 iMac up to 128GB
877-865-7002
Today’s Deal Zone Items... Handpicked deals...
$1199 $779
SAVE $420

$250 $200
SAVE $50

$1699 $1299
SAVE $400

$1499 $1149
SAVE $350

$200 $140
SAVE $60

$89 $69
SAVE $20

$120 $35
SAVE $85

$178 $148
SAVE $30

$3498 $2998
SAVE $500

$3699 $1299
SAVE $2400

$1000 $700
SAVE $300

$3899 $1499
SAVE $2400

$748 $648
SAVE $100

$2999 $1999
SAVE $1000

$1699 $999
SAVE $700

$1698 $1398
SAVE $300

$4499 $4499
SAVE $click

$1399 $1049
SAVE $350

$1149 $799
SAVE $350

$1399 $1049
SAVE $350

$1498 $1198
SAVE $300

$2797 $2597
SAVE $200

$280 $250
SAVE $30

$699 $699
SAVE $click

$1699 $1299
SAVE $400

$8399 $8399
SAVE $click

$899 $799
SAVE $100

$1699 $1299
SAVE $400

Reader Question: DiskTester and OS X Cache

Reader Frank W writes:

Do DiskTester files land in a system (or other) cache?

MPG: DiskTester bypasses the OS X unified buffer cache so that all its tests are actually reading and writing to the drive. This is mandatory for any meaningful results.

The drive (HDD, SSD) or a controller card might have its own cache; this is all “the drive” and is necessarily part of the test.

The DiskTester fill-volume test is useful for characterizing drive performance, whatever the type of drive.

DiskTester fill-volume produces output that can be pasted into a (supplied) Excel graph template so that volume performance can be interpreted at a glance (“volume”, not “drive” — a single drive or multi-drive RAID or an SSD or whatever is tested as a file system volume).

  • For hard drives, the graph shows how performance declines across the volume (see The Fastest 2TB Volume is on a 4TB Drive and related articles). It also shows if there are any oddball irregularities, which could indicate a marginal drive.
  • For solid state drives (SSDs), the graph makes any performance breakdowns or irregularities visible.
  • For RAID or any other type of device, the same ideas apply.

For a Fusion drive, the graph below makes clear the abrupt loss of performance when the SSD fills up.

Write and read speed of 256GB 2nd batch (512GB total) on 480GB SSD + 2TB Fusion volume
OWC Envoy Express

World’s first Thunderbolt 3 M.2 NVME SSD enclosure.

Super fast, bus-powered, 3.3 oz, DIY easy, rugged and compact!


See also OWC Express 4M2
√ No more slow and noisy hard drives!
OWC Accelsior 4M2 PCIe SSD
6000 MB/sec!
Mac or PC.


Ideal for Lightroom, Photoshop, video.
Capacity up to 16TB!
OWC Thunderblade Thunderbolt 3 SSD

Blazing fast, up to 16TB.

YEE HAH!



√ No more slow and noisy hard drives!
OWC Envoy Pro EX SSD
Blazingly fast Thunderbolt 3 SSD!

Up to 4TB capacity, USB-C compatible.

USB-C model also available


Great for travel or for desktop!

Deals Updated Daily at B&H Photo
View all handpicked deals...

LG UM7370PUA 70" Class HDR 4K UHD Smart LED TV
$1199 $779
SAVE $420

diglloyd.com | Terms of Use | PRIVACY POLICY
Contact | About Lloyd Chambers | Consulting | Photo Tours
Mailing Lists | RSS Feeds | Twitter
Copyright © 2020 diglloyd Inc, all rights reserved.
Display info: __RETINA_INFO_STATUS__