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SanDisk User
Posts: 25
Registered: ‎12-30-2013

Re: How is ExpressCache 1.3.2 working?

[ Edited ]

I re-formatted my PC and installed Windows 8.1 with Update x64.  I thought I would give ExpressCache 1.3.2 another shot at working without modification.  But, once the cached filled up it start causing problems like my PC taking forever to boot up.

 

I took the suggestion above and capped my cache at 25Gb.  That has helped.

 

Sandisk when is this going to get fixed!!!!!  This is taking way too long to release updates for this product.

SanDisk User
Posts: 34
Registered: ‎05-08-2013

Re: How is ExpressCache 1.3.2 working?

[ Edited ]

Well, to finally confirm it: after >month and a half of use with only 16GB this computer exibited no readycache related problems. No winlogo temporary freezes or later catastrophic system freezes while running windows with near full cache. I'll try a 3/4 full drive now (22900KB) excluding again dedicated storage and download drives (torrents mess up cache badly by creating too much cached activity, wich leads to a quicker purge of more important system data). As I've had repeated trouble with only about ~22-24GB filled, I'll undershoot 25GB a bit more than suggested.

 

I've used for a short time a laptop with a 24GB mSATA cache drive using readycache, and there seem to be no issues. This ssd almost full all of time, because on one partition it held hybrid boot data (maintained by other program), and the remaining ~16GB were kept close to full.

Then again, I guess overprovisioning should yeld better IOps (specially on writes) and drive longevity for wear leveling, but such freezes on startup that take a lot of seconds seem more related to a software fault (as NWGuy pointed) than the added latency of a non-optimized SSD/weak controller. Hence why less cached data up to some 20-25GB might strain less the software.

 

I also believe that many cache reset problems can be due to windows updates, file scans, scheduled defrags, hours of torrenting + moving files, that cause havoc on the LBA list, leading to an expected total resynch.

SanDisk User
Posts: 22
Registered: ‎02-12-2014

Re: How is ExpressCache 1.3.2 working?

AlleyViper,  here's why I'm thinking you can go up higher than 23Gb without delays, even though you and others have seen issues starting near that point:   As far as I know, all these reports were based on running the full available OEM 29.82 Gb size for the active partition!

 

Now if that is not the case, and if you have experienced cache delays with smaller partition sizes, by all means don't go above what  works for you -- and please post here.

 

We also need to be sure everyone reporting has upgraded to firmware 1.3.2, as bug reports of all kinds have decreased significantly with that revision, and I know some of the posted delay issues involving partition fill percentages were posted using prior firmware.

 

OK, here goes:  How a cache works.

 

You start with a certain low number of disk reads per time period or reboot cycle to initially fill the cache -- lets say you start by caching LBAs that have 5 reads to start with.

 

At some point your cache gets close to full (let's say 80%) -- clearly caching all LBAs with 5 reads is going to take more space than available.   So you want to increment the required LBA read count to be cached by one, making it 6 in this case, and then delete any cached LBAs with fewer than 6 reads from the cache.

 

In my case with a 16 Gb partition, I observed the cache filling, then decreasing, then refilling again, just as you would expect -- with slight boot delays where you would expect housekeeping to be clearing out deleted low activity LBAs.   I've observed several cycles, the highest cache fill I've observed was 86.25%, the lowest (after initial fill) was 76.25%.

 

What people are observing using the OEM 29.82 Gb partition is that the initial cache housekeeping pass, triggered somewhere around 80% fill, is taking a lot longer than 5 seconds or so to complete  -- yet initial housekeeping passes on smaller partitions finish quickly -- disproportionately quickly.     It's possible that some absolute number is being exceeded -- say I did a "scan every file" virus scan over and over again to try to max out the array of LBA read counts -- but my guess is that that scenario has been anticipated.   Most likely is that we're running out of what I'll call 'scratch space' when the partition is set to 29.82 Gb.

As an example, when deleting slower moving LBAs, one may wish to populate a separate array for housekeeping to work off of -- perhaps there is not enough room in the 2.18 Gb (code?) space between 29.82 Gb and 32 Gb for this array.   Maybe at one time everything fit but some code change ended up taking more space.

 

If that's the case, it MAY be a very near miss -- maybe a 29.81 Gb partition would work.   Most likely, making another full 2.18 Gb available by reducing the active partition size to 29.82 - 2.18 = 27.64 Gb would work.  That would cover the "Oh, I thought I had the entire 2.18 Gb space for data structures!" scenario.  Not that that sort of thing ever happens Smiley Happy   Or is likely happening, as everyone’s cache would be affected.

 

HOWEVER, there's always the chance that something does happen as cache fill nears 23 Gb in absolute terms.  Having observed a maximum fill of 86% prior to housekeeping, let's say 90% to be safe,   a 25 Gb partition x 0.9 = 22.5 Gb, so AlleyViper, I really think you will be 'safe' with a 25Gb partition.

 

There is another possibility too.   We’ve been addressing this problem by reformatting and repartitioning the drive using firmware 1.3.2 – what if that is all that’s necessary?    Hs anyone tried a ‘clear out and start over’ from the command line using firmware 1.3.2 and the OEM partition size? 

SanDisk User
Posts: 34
Registered: ‎12-08-2013

Re: How is ExpressCache 1.3.2 working?

@NWGuy,

 

Perhaps SanDisk should simply fix the software?

ReadyCache is supposed to be transparent to the user.

 

I will never buy a SanDisk SSD type product again.

Could you blame me?

 

Flavio Smiley Mad

SanDisk User
Posts: 34
Registered: ‎05-08-2013

Re: How is ExpressCache 1.3.2 working?

[ Edited ]

@NWGuy

 

Btw, the partioned 29.82GB are already the full declared ~32GB without any spare/scratch or provision space (that would be the case of a drive sold as 30GB with the remaining 2GB unacessible for provision). Manufacturers use Gigabytes (1000^3) instead of formated Gibibytes (1024^3) for storage space.

This 32GB ssd has 62533296 available physical sectors with 512 bytes per sector, which gives 32017047552 bytes (~32000000000) or 32.02GB. If you divide those bytes for 1024 three times, you'll end up with 29.82GB as commonly reported by an OS that prefers a 1024 base instead of 1000 (or, more precisely, 29.82GiB).

 

For now, I'll keep this 3/4 partition to check for abnormal delays or freezes. Given that this drive receives no TRIM commands from Windows because it hasn't an atributted drive letter, a guaranteed 25% free space should be good enough for its own housekeeping and wear leveling (independently of current readycache software issues).

If everything goes well, I'll reclaim I bit more space as you suggest.

 

Btw, you're right in your assumption, every freeze I've had with 22-24GB filled, and once even with 17GB was under a 29.82GB full sized partition. Unfortunately this testing will take some time, as I'm not always near this PC.

 

 @Flavio

 

No one here is happy with this situation, the only "good" sign, is Sandisk acknowledging the issues and the hope for a fix. As a matter of fact, I've retired my readyache to a PC I've built for a familiar because of all of the frustrating problems and went with a decent sized SSD on my desktop from another brand. This was more than half a year ago.

If it was working right from the start, or even the way its finally working now with these workarounds, that investment wouldn't be necessary. Just try to reduce your cache partition size, and your experience with this drive might be less frustrating. You have nothing to lose until there's a proper fix.

Highlighted
SanDisk User
Posts: 22
Registered: ‎02-12-2014

Re: How is ExpressCache 1.3.2 working?

AlleyViper, can't believe that got by me, especially since I've had the SSD partition pulled up on Partition Wizard more than once -- thanks for the good explanation.

 

I just had a cache 'reset' happen to me on my OEM partitioned unit at somewhere between 26.3 and 27 Gb  -- 26.3 was the last reading I saw working and the cache was filling very slowly at that point.   The following shutdown took a long time (minutes) of disk activity, and the next bootup went very slowly, with Windows logo delays.  When I looked at the cache it was starting over at 0.07 Gb, but it started filling again, up to 3+ Gb in 10 minutes and 12+ Gb by the end of the day.

 

29.82 x 0.90 = 26.84

29.82 x 0.86 = 25.65

The delay issues I've seen occured in this range

 

29.82 x 0.78 = 23.26

29.82 x 0.74 = 22.07

With the exception of your 17Gb observation, around 75% is the lowest cache fill reported with observed delays, with more reports around 80%.

 

  

Both my caches are working fine overall and are definitely speeding up disk IO and reducing physical disk wear and tear.

 

I don't mind occasional small housekeeping delays at bootup -- maybe because that's how I expect a cache to work.    I don't mind leaving some working space for cache operation -- that's the easy fix for Sandisk, just reduce the OEM partition size.

 

AlleyViper will be trying around a 23 Gb partition.  I'm going to try 25 Gb on both of mine.   It would be great if someone could try 27 Gb, watching cache size daily once fill exceeds 23 Gb.  It may be awhile before I report back.

SanDisk User
Posts: 22
Registered: ‎02-12-2014

Re: How is ExpressCache 1.3.2 working?

Well, things didn’t go as I planned – and I learned some things.

 

On the machine I had tried the 16 Gb partition on I decided to try a 27 Gb partition, and start the GUI splash screen with Windows to keep a close eye on the numbers.

 

Oddly enough, even after the command line steps including clearing the old partition and formatting the new partition, the cache seemed to start with the 12+ Gb fill it had on the 16 Gb partition – so I guess those eccmd commands don’t clear the “LBAs to be cached” table.     Wanting a fresh start, I used Clear Cache from the Options on the GUI and that started the partition over at 0.07 Gb .

 

Now on the other computer, the one with the never modified original partition, remember it had recently reset after getting quite full and was refilling much more rapidly that it had the first time.   Well, it has been operating fine ever since, roughly in the 75% to 85 % fill range – no resets.  Also interestingly  I’ve observed it making decreases in cache size during cache operation – I’ve watched on Task manger, during these times both Express Cache and the Express Cache Service grab 25 to 30 Mb of memory and consume around 1.5% CPU.   Very good performance in my opinion.    Now I can’t say for sure whether the actual NAND housekeeping  occurred ‘live’, but I can say there were no major boot delays either before or after cache decreases.

 

Summarizing, what I observed was a very slow cache fill (many days) for the first time through, then a cache reset to 0.07, and then a very fast cache fill and normal cache operation thereafter.

Now back to the 27 Gb machine – I observed the exact same pattern – slow fill, reset, fast fill, normal operation.

 

When the reset occurred, however, on this machine I was loading the GUI at startup, and an additional text box appeared  (In my words I didn’t write it down):  “The cache has been reset so operations will be at normal speed.   Cache resets can be caused by . . .” and it several things including a Windows update.

My conclusion is, this program is currently designed so that the first time you use it, it will fill the cache slowly while generating an LBA use table, then clear the cache and start over with that table.    I don’t remember reading that anywhere so maybe Condusive and Sandisk need to explain a little more what normal operation is so folks aren’t surprised when the cache resets.

 

I also think Sandisk needs to make two changes to the GUI.   First, the informative text box that a cache reset has occurred should display whether or not you are starting the GUI with Windows.   Second, the small ExpressCache icon should load in the system tray by default, again whether or not you are starting the GUI with Windows.

 

For folks who, for whatever reason, want to avoid any cache reset EVER, it may not be possible, although I don’t remember ever seeing a cache reset when I had the partition size down to 16 Gb.

SanDisk User
Posts: 22
Registered: ‎02-12-2014

Re: How is ExpressCache 1.3.2 working?

Both of my ReadyCaches have been running without any resets for over a month, so I'm going to end my partition size reduction experiment and return the one I had reduced to 27Gb to the OEM 29.xx Gb size.

 

I think that occasional cache resets may occur as part of normal cache operation during the first 30 days of use or so, but after that rarely.  I think that Sandisk/Condusive needs to better communicate this to users so folks are not surprised when it happens.

 

 

Newbie
Posts: 5
Registered: ‎06-20-2014

Re: How is ExpressCache 1.3.2 working?

I've been running Condusiv 1.3.2. version since April 30th, 2014.  ReadyCache was bought on April 29th and both the SSD and 1.3.2 were installed on the 30th.

 

System is a HP.Compaq dx2300 business minitower with two SATA HDDs.  OS drive is SATA II, whislt the other drive is SATA III.  All system SATA ports are SATA II. 

 

Drive C is SATA 0, DVD-ROM is SATA 1, Drive E is SATA 2, and the Sandisk SSD ReadyCache drive is SATA 3.

 

Original configuration was as above, and original ReadyCache setting was 28.92 GB.

 

Worked fine most of the first day, until Acronis ran the daily image backup @ 5:00 AM.  Then the cache went from ~6.00 GB to max several times in only 60 minutes and reduced to ~23-27 GB and then finally settled down.

 

I'm sorry, but removing Acronis is not an option.  There was, and is, clearly a cause and effect on system and SSD performance after the imaging software is run.

 

Experimentation via reducing the formatted cache size is still ongoing.  I've tried 8.00 GB (recommended by Sandisk tech support), 23.00 GB, and now 16.55 GB currently.  With 8 GB, no windows system logo hang was noted, 23 GB sometimes, and now, with 16.55 GB I'm hoping for some stable operation w/o system freezes or logo hangs on boot or restart.

 

Seems to me the issue I'm seeing is that there are no options within the Condusiv software to ignore data generated by Acronis True Image or any imaging software when a daily backup is done.  I see the same sort of uptick in total system and cache reads.when the a/v program or Malwarebytes is told to do a manual scan, but this data does not need to be cached for any of these programs to run, so why is there no option in the Condusiv software to tell the drive to not cache this data?

 

It's not possible to anticipate every possible configuration a consumer will have on their system, and also all data generated by any system does not have to be cached in order for a SSD cache drive to perform satisfactorily; one should be able to exclude certain types of program activity (active file scanning by antimalware programs or imaging programs in this case) from the cache drive.  Reason this is so, is because the data generated by these sort of programs always seem to have a negative performance impact on the SSD drive.  (The fact that this SSD is of older technology does not help.)

 

Condusive does not, and has not, offered this option.  Wish I'd known that before I bought the product.  Offering this option would go a long way in customer perception and satisfaction and make the promise of a faster, more stable, more reliable system more possible for everyone.

 

It should be perfect for an older system, and when it works as it should, it's great. 

 

But here one size does not fit all, and there has to be a way to fit the software to the actual system configuration and differing customer needs.

 

Offering this option alone would take care of the LBA backlog and tabling issues, and minimize cache resets.  It's the logo hang that is the most bothersome to me, so for now I'm  working with the 16.55 GB volume size which should eliminate the logo hang forever.  With the proper exclusions available, it should be possible to run the SSD at 29.82 GB and have the expected speed and operation,and cache size one paid for. 

 

As it is, it is not possible unless one formats the drive to ~16 GB, as other users have posted here.

 

Will Condusiv consider making such options available in the next oem release?  Will they make it happen?  I think it is certainly worth a try as a beta release.  If that works, then go oem.

 

 

SanDisk User
Posts: 22
Registered: ‎02-12-2014

Re: How is ExpressCache 1.3.2 working?

Identifying every backup, defragging, etc. type program inside the Conducive software would be very difficult.  And you can't turn the cache off temporarily, lest the data in the cache gets out of sync with the data on the hard drive -- that is, unless you flush the cache entirely and start over.

 

I personally can't figure out how to avoid occasional boot time delays with an algorithmic filled cache.