Defragmentation and RAM question

On 11/19/2017 6:09 PM, Wolf K wrote:
On 2017-11-19 17:43, Keith Nuttle wrote:
On 11/19/2017 3:56 PM, s|b wrote:
On Sun, 19 Nov 2017 09:37:47 +0000, Scott wrote:

2.Â* Would doubling the RAM to 16GB make a significant difference?

I've always been told: more RAM is interesting if you have a lot of
programs open at the same time (or programs thatÂ* use a lot of memory).
If you want speed, invest in a better/faster CPU.

Why does a thumb drive or other solid state drive not need defragmenting?

It seems like it would be subject to the same forces that cause
fragmentation in the first place.
:


Files written to a solid state memory chip may of course be fragmented,
ie, their sectors may not be next to each other (con-tigu-ous, or
together-touch-ing). But since a solidstate chip is read differently
than a spinning disk, fragmentation makes no difference.

In practice, fragmented files don't matter. You are the slowest
component of the system, so even if fragmentation slows down read/write
time, you won't notice.

That is the way I understood it, and I guess since the points are fixed
on a solid state drive I see why it does not have to be defragmented.

--
2017: The year we learn to play the great game of Euchre

Defrag in Windows 10 runs the Trim command.


KenW

On Sun, 19 Nov 2017 21:56:44 +0100, "s|b" wrote:


On Sun, 19 Nov 2017 09:37:47 +0000, Scott wrote:


2. Would doubling the RAM to 16GB make a significant difference?


I've always been told: more RAM is interesting if you have a lot of
programs open at the same time




That's not true. What you have open has very little effect on RAM
usage. It's what you are actively *using* that affects RAM usage.
That's because if you don't have enough RAM for all your open
programs, programs you are not using quickly get paged out and *stay*
paged out until you use them again. Paging slows you down only if
things constantly are paged in and out.



(or programs that use a lot of memory).




Yes, if you are actively using such programs.

But also note that whether or not more RAM is interesting depends not
only on what programs you are actively using, but also on how much RAM
you have. For example, most people with 16GB would not find an
improvement in adding RAM, even if they are using big programs.

Keith Nuttle wrote:
On 11/19/2017 3:56 PM, s|b wrote:
On Sun, 19 Nov 2017 09:37:47 +0000, Scott wrote:

2. Would doubling the RAM to 16GB make a significant difference?

I've always been told: more RAM is interesting if you have a lot of
programs open at the same time (or programs that use a lot of memory).
If you want speed, invest in a better/faster CPU.

Why does a thumb drive or other solid state drive not need defragmenting?

It seems like it would be subject to the same forces that cause
fragmentation in the first place.
:


The seek time on solid state drives is very low.

There's a table here, showing just how low the latency is.
I use 20-100 microseconds as an estimate. There's probably
a difference between read and write.

http://www.tomshardware.com/news/sam...ane,35956.html

On an SSD, it doesn't matter whether you read adjacent
locations or distant locations, there's no penalty
(relatively speaking). There is no "head" to move around.
Everything is done with "digital addresses".

Whereas if two fragments are at either end of a rotating HDD,
it might take 12 milliseconds to move the heads there.
That can give an incentive, in some situations,
to move the fragments closer together (defragment).

For a large backup image file (a 40GB MRIMG file representing
an entire C: partition), if it had seven fragments, you
wouldn't care. If you managed to put 100,000 fragments
into it, then you might care (there are ways you can do
that by accident, so that isn't as far fetched as it sounds).

However, it's a lot of work to "optimize" that file,
if you're only going to read it the one time. Optimization
is more worthwhile, if the file or disk area, is used
over and over again in a wasteful manner. Then, you might
see some benefit from your efficiency push. For example,
the C: drive gets scanned on Win10 for various reasons,
and if a HDD is involved, you could be gaining some small
benefit from keeping it defragmented. But not as much
benefit as the advertising page trying to sell you a
defragmenter :-)

Paul

To: Ken Blake
Defragmentation and RAM question
By: Ken Blake to alt.comp.os.windows-10 on Sun Nov 19 2017 12:02 pm


Then you probably have more RAM than you need. Buying more would be a
waste of money.


Interestingly, Elder Scrolls Online requires a minimum of 18 GB to run.Maybe
the future has arrived?

Mick


Central Ontario Remote BBS
Fidonet 1:249/307 fsxNET 21:1/156
--- Synchronet 3.16c-Win32 NewsLink 1.103
Central Ontario Remote BBS - telnet://oxfordmi.synchro.net

On 11/19/2017 8:15 PM, Mickey wrote:
To: Ken Blake
Defragmentation and RAM question
By: Ken Blake to alt.comp.os.windows-10 on Sun Nov 19 2017 12:02 pm


Then you probably have more RAM than you need. Buying more would be a
waste of money.


Interestingly, Elder Scrolls Online requires a minimum of 18 GB to run.Maybe
the future has arrived?

Mick


Central Ontario Remote BBS
Fidonet 1:249/307 fsxNET 21:1/156
--- Synchronet 3.16c-Win32 NewsLink 1.103
Central Ontario Remote BBS - telnet://oxfordmi.synchro.net



18GB! could you tell us where you got that info or give us a link.

Rene

On 11/19/2017 8:43 PM, Rene Lamontagne wrote:
On 11/19/2017 8:15 PM, Mickey wrote:
Â*Â* To: Ken Blake
Â*Â* Defragmentation and RAM question
Â*Â* By: Ken Blake to alt.comp.os.windows-10 on Sun Nov 19 2017 12:02 pm

Â*
Â* Then you probably have more RAM than you need. Buying more would be a
Â* waste of money.
Â*

Interestingly, Elder Scrolls Online requires a minimum of 18 GB to
run.Maybe
the future has arrived?

Mick


Central Ontario Remote BBS
Fidonet 1:249/307 fsxNET 21:1/156
--- Synchronet 3.16c-Win32 NewsLink 1.103
Central Ontario Remote BBS - telnet://oxfordmi.synchro.net



Â*18GB! could you tell us where you got that info or give us a link.

Rene



Never mind, I just researched it on Steam and the memory requirement for
Elder Scrolls online is 4GB, Else barely anyone would be able to play it.

Rene

Mickey wrote:
To: Ken Blake
Defragmentation and RAM question
By: Ken Blake to alt.comp.os.windows-10 on Sun Nov 19 2017 12:02 pm


Then you probably have more RAM than you need. Buying more would be a
waste of money.


Interestingly, Elder Scrolls Online requires a minimum of 18 GB to run.Maybe
the future has arrived?

Mick


Central Ontario Remote BBS
Fidonet 1:249/307 fsxNET 21:1/156
--- Synchronet 3.16c-Win32 NewsLink 1.103
Central Ontario Remote BBS - telnet://oxfordmi.synchro.net

You were probably seeing comments about some
patcher download. The patcher download might be bigger
or smaller than the quantity on disk.

The requirements for the game itself, there's
an example here. You can see they didn't want to
move the user population "to the future". This
is kind of a yesterday spec. This is a minimum
requirement.

https://www.geforce.com/games-applic...m-requirements

"Minimum System Requirements

Operating System: Windows XP 32-bit
Processor: Dual Core 2.0GHz or equivalent processor
Memory: 2GB System RAM
Hard Disk Space: 60GB free HDD space
Video Card: DirectX 9.0 compliant video card
with 512MB of RAM (NVIDIA GeForce8800 / ATI Radeon 2600)
Sound: DirectX compatible sound card
"

When a game has textures, they don't all have to be
loaded at one time. They can be paged in, as you
change levels or move your physical location on
the map.

Microsoft Flight Simulator does that. It has a process
that "looks ahead" in the direction you are flying, and
reads the hard drive for map info to make terrain with.

Paul

On Sun, 19 Nov 2017 21:53:51 +0100, "s|b" wrote:

On Sun, 19 Nov 2017 09:37:47 +0000, Scott wrote:

My external drive used for Acronis backups is taking about a day to
defragment using Norton.
1. Is there any point in defragmenting such a disk at all if it is
only a backup?

What's your external drive? For instance, I have a LaCie Rikiki which
doesn't have any moving parts.

Did you replace the HD with a SSD?

AFAIK there's no point in trying to
defragment it, just like you wouldn't defragment a USB flash drive.

Defragmenting an SSD would shorten it's life.

On Sun, 19 Nov 2017 21:56:44 +0100, "s|b" wrote:

On Sun, 19 Nov 2017 09:37:47 +0000, Scott wrote:

2. Would doubling the RAM to 16GB make a significant difference?

I've always been told: more RAM is interesting if you have a lot of
programs open at the same time (or programs that use a lot of memory).
If you want speed, invest in a better/faster CPU.

Lots of RAM is good in a server. Some have terrabytes of RAM.

In article , lid
says...

On Sun, 19 Nov 2017 09:37:47 +0000, Scott wrote:

2. Would doubling the RAM to 16GB make a significant difference?

I've always been told: more RAM is interesting if you have a lot of
programs open at the same time (or programs that use a lot of memory).
If you want speed, invest in a better/faster CPU.

If you want to know if more RAM would speed up your system, download
Process Explorer from:
https://live.sysinternals.com/procexp.exe
manual at:
https://live.sysinternals.com/procexp.chm
(Sysinternals is now part of Microsoft, so these are safe downloads.)

Open it (no install needed) and leave it minimised (not sure you even
have to have it running). Near the end of your session, Click:
View / System Information
.... and go to the Memory tab,

Look in the "Commit Charge" pane - this shows the amount of memory the
system and programs have demanded. "Peak" is of particular interest.
Compare it with the "Total" shown underneath in the "Physical Memory"
pane. If Total is greater than Peak, then your system has always
(during the current session) been able to meet all demands on memory
without swapping out to disk (a very slow process, relatively). Adding
more memory would have made no difference to the present session.

Look now at Current Commit Charge. If that's less than Total Physical
Memory, then your system doesn't have enough memory for what you're
doing right now. If the difference is proportinately small, then it may
not be too bad, but if you're constantly flicking between programs, then
you're going to see a noticeable wait at some point.

It can be instructive to open your machine, take half the memory out,
and do this test again!

--

Phil, London

On Mon, 20 Nov 2017 11:33:07 -0000, Philip Herlihy
wrote:

Look now at Current Commit Charge. If that's less than Total Physical
Memory, then your system doesn't have enough memory for what you're
doing right now.

Should read "more" not "less", shouldn`t it? Process Hacker 2 has some
nice tray icons for these metrics:
http://processhacker.sourceforge.net

I prefer looking into the Windows Task Manager and look how much cache
is used in RAM. The system will run faster if it can cache data to
some GB of RAM (I assume).

Regards

M.

Michael Logies wrote:
On Mon, 20 Nov 2017 11:33:07 -0000, Philip Herlihy
wrote:

Look now at Current Commit Charge. If that's less than Total Physical
Memory, then your system doesn't have enough memory for what you're
doing right now.

Should read "more" not "less", shouldn`t it? Process Hacker 2 has some
nice tray icons for these metrics:
http://processhacker.sourceforge.net

I prefer looking into the Windows Task Manager and look how much cache
is used in RAM. The system will run faster if it can cache data to
some GB of RAM (I assume).

Regards

M.

There are two kinds of RAM cache at work.

There is the System Read Cache. It's free :-) It
doesn't cost anything. It can use the entire RAM,
if you're not using the RAM for anything else.
The System Read Cache gives up the RAM, if any
other activity asks for it, and gives up the
RAM instantly. It's basically a free lunch.

Say you have 16GB of RAM. You use a checksum
program, to compute a checksum on a 15GB file.
The file is read from the hard drive at 100MB/sec.
The job takes 150 seconds to do. Now, you decide
to compute the checksum a second time. The file is
now resident in the System Read Cache. The checksum
program happens to run at 1GB/sec. The RAM is faster
than that, so the System Read Cache is not the bottleneck.
Now, the second attempt to compute the checksum
takes only 15 seconds (at 1GB/sec). That's ten
times faster. If the checksum program is really
slow (SHA256), then the read cache doesn't help
at all, and all the calcs are the same speed.
But where normally the disk would be the bottleneck,
getting the file the second time, from the
System Read Cache, really helps.

You'll also see this sometimes, when the "detailed"
File Copy dialog is present on the computer screen.
There will be a taller rectangle at the beginning
of the copy, where the System Read Cache is supplying
data, instead of the hard drive.

*******

The other cache is the System Write Cache. It is "charged"
when used, in the sense that the RAM it uses, cannot easily
be released in a hurry. The cache has to drain, before
the RAM is returned to the system. Let's say for the sake
of argument, that no more than 1/8th of system RAM can
be used for the System Write Cache.

Say you start a file transfer from a fast disk, to a slow disk.
And no other programs are running. The Task Manager says that
maybe 1GB of RAM is occupied. Your system has 26GB og RAM,
minus the 1GB for the system, leaves 15GB, and 1/8th of
that is approximately 2GB.

As the file copy happens, you notice the RAM usage increase
from 1GB (system part) to 3GB (system+write_cache). Now, the
cache is full, and it only drains if the output side of the
queue has a chance to drain to disk. So once the cache is
full, the transfer to disk is again limited by the disk speed.
The cache only really helps for small transfers (as the write
operation can then be completed when you're doing other things).

The danger with the system write cache, is the power could go
off. To drain a 2GB cache to a hard drive, at 100MB/sec,
takes 20 seconds. That means my UPS has to stay up for at least
those 20 seconds, so the queue can successfully drain to disk.

*******

Those are two caches on your computer.

RAM is used for a few more things - the evidence of that, is
the 1GB the OS takes while sitting idle, if you put the
system under memory pressure, the OS portion shrinks to
350MB. That tells you that 650MB is being used for
some other kinds of structures, but they're expendable
structures (like the system read cache) and other programs
can use that RAM if they malloc it.

*******

Of the two caches, the System Write Cache is crap. On some
of the Windows OS, it tends to stutter and slow down
file copying. It can have "digestion" problems.

The System Read Cache is great, except, the OS doesn't
honor it. Win2K made real good usage of the System Read
Cache. Later OSes use it to a lesser extent, and tend to
go to the disk, when a perfectly good copy is in
the System Read Cache. So it doesn't really pay to
"warm up" the cache for certain kinds of operations.
For example, the disk defragmenter, refuses to use
that cache on a read.

Paul

On Mon, 20 Nov 2017 09:16:43 -0500, Paul
wrote:

There are two kinds of RAM cache at work.

Paul.

thanks a lot for clarification!

Of the two caches, the System Write Cache is crap.

I can recommend Primocache instead:
https://www.romexsoftware.com/en-us/primo-cache/

I`m using it with a write cache of 15 s and 1 GB RAM (the Win 7-host
of my VMs is a bit RAM-restricted with 24 GB) for a Software-RAID1
between a SSD and a harddisk (with Mirrorfolder,
https://www.techsoftpl.com/backup/) but I have read of people using it
for buffering writes for hours (!), then discarding all the changes
when the user logs off. That speeds up a terminal server a lot.
Using the write-cache of Primocache makes UPS mandatory.

Regards

Michael

On Sun, 19 Nov 2017 21:15:41 -0500, "Mickey"
-pf3-this wrote:


To: Ken Blake
Defragmentation and RAM question
By: Ken Blake to alt.comp.os.windows-10 on Sun Nov 19 2017 12:02 pm



Then you probably have more RAM than you need. Buying more would be a
waste of money.



Interestingly, Elder Scrolls Online requires a minimum of 18 GB to run.Maybe
the future has arrived?




I never heard of Elder Scrolls, but as I said, there are some very
specialized programs that require more RAM.

8GB is more than most home users need.