Intel X-25m G2 losing performance?

[flamenko]

None of your drive should be unpartitioned and you can have as many logical partitions as you wish.

I have the same drive and, actually, if you partition it as I leaving only the OS and applications on the drive and then leave about 20% free on that partition, you will be golden.

 

[HendrixFan]

Just to make sure I understand, the whole drive can be partitioned, and the free space can be on that partition or do I need to leave some unpartitioned?

I have a 160GB Intel X25-M G2, with about 35% free space(partitioned) at the moment.

As far as I am aware, it would affect you having it partitioned.

SSD drives need free space so that they can do garbage collection and wear leveling. As you add and delete files the drive goes through and reallocates the data so 2 half empty blocks become one full one and one empty one. Leaving free space allows the drive to just write freely and worry about organizing the data later, while the drive is "idle". A full or near full drive will perform those functions on the fly as you are trying to write the data and you will see a huge drop in performance.

I'm not positive on how windows partitions drives (especially for SSDs, if there is any difference) but I'm pretty sure it sets aside a physical section of the drive for that partition. That is how short stroking works, by taking the fastest part of a spinning drive and using it for a partition.

Say you have a 100GB drive, and you make an 80GB and 20GB partition. If you fill up the the 20GB partition and have room free on the 80GB windows will still tell you the drive is full. I don't think windows allows the "two" to cross paths. With a SSD, the free space is needed for wear leveling and garbage collection. If one partition is full, then it shouldn't use the other empty one for those functions.

You can however leave part of the SSD unpartitioned and the drive will automatically use that as it sees fit. In the scenario above you would still have a 100GB drive, but you would partition 80GB of it and leave the other 20 unpartitioned. The Sandforce drives basically do this for you automatically. The 50GB drive is really 64GB of flash but the user is only able to access 46.6GB of it. The rest is used for the drive to take care of business. The 100GB model has 128GB of flash, the 200GB has 256GB of flash. A third of the drive is already set aside so the user doesn't have to leave the drive empty.

Intel and others should follow their lead so uninformed users don't get stuck wondering why they have performance degradation.

If I am wrong on a windows partition not working for GC and wear leveling please chime in! I do know for a fact unpartitioned space works, but I'm pretty sure (but not positive) that a separately partitioned space would not. Free space within a single partition certainly works as well.

 

[jimhsu]

I'm not sure that I can demonstrate that, for example, a 74.5GB partition with 15GB of free space is different from a 59.5 GB partition. If yes, I'm off to resize my partitions (after a backup, of course). Anyone care to do some tests?

 

[jimhsu]

If I am wrong on a windows partition not working for GC and wear leveling please chime in! I do know for a fact unpartitioned space works, but I'm pretty sure (but not positive) that a separately partitioned space would not. Free space within a single partition certainly works as well.

If the Intel drive (as all SSDs now do) maps logical to physical blocks, it theoretically should not matter if the space is unpartitioned, partitioned, on a different partition, etc. Filesystems are just a list of 1's and 0's as far as the physical media is concerned. Now, that's only "theoretically".

 

[Voo]

Yeah I'd say it's highly unlikely that the controller has the slightest notion of filesystems or partitions at all. If it had Intel and Co would have to support dozens of different filesystems for no particular benefit. You surely get performance gains if you have more free space, but I don't see the correlation to partitions or filesystems. As long as nothing is written to a particular cell the controller can use it for whatever he wants, why care about anything else?

Also it's not as if it was impossible to write something to unparitioned space..

 

[Old Hippie]

In the scenario above you would still have a 100GB drive, but you would partition 80GB of it and leave the other 20 unpartitioned.

I'm thinking you probably mean an unformatted partition for the "scratch area"?

I left a 20GB unformatted partition for this free area even though I rarely have more than 50GB used out of the 140GB RAID0 partition (2 Intel 80GB - drive C).

I'm not sure if formatting the 20GB partition would make any difference.

 

[IntelUser2000]

The Sandforce drives basically do this for you automatically. The 50GB drive is really 64GB of flash but the user is only able to access 46.6GB of it. The rest is used for the drive to take care of business. The 100GB model has 128GB of flash, the 200GB has 256GB of flash. A third of the drive is already set aside so the user doesn't have to leave the drive empty.

Intel and others should follow their lead so uninformed users don't get stuck wondering why they have performance degradation.

Intel drives do that as well. Just that on the X25-M, the drive specified space is much smaller. 80GB drives have 74.5GB user accessible space.

Intel mentions that while you can partition the space for better worst-case performance, you'd want to do Secure Erase after that.

Another thing. On the early reviews, Intel X25-M was mentioned to have "Advanced Dynamic Wear Levelling". Basically what Dynamic Wear Levelling does is it only moves "dynamic data" and leave "static data" alone.

 

[jimhsu]

In Anand's new article, he demonstrated that the Sandforce is indeed overprovisioned: http://anandtech.com/show/3690/the-...andforce-more-capacity-at-no-performance-loss

That's some impressive figures. I wonder what the controllers are doing to be able to minimize the impact of spare area so much.

 

[Sunburn74]

Make sure hibernate and system restore are turned off for your windows install. If you have 8gb of ram, hibernate takes 8gb of your harddrive space away from you. If you have 4gb, it takes 4gb of hard drive space.

System restore too also can insidiously steal space from you.

Otherwise I dunno. I assume you have the latest drivers as well and have write caching turned on. Not really sure what to tell you man other than maybe consider uninstalling stuff or moving files to a storage drive.

 

[Reven]

Hi

I've been having the same problem again, and was wondering if anyone could be of aid. I have the same set-up, a Intel X-25m G2 80gb as my system drive and an additional X-25m G1 80gb as a game drive.

The odd thing is the system drive seems rather slow. I am getting a '5.9' windows performance index on the drive. I have 21gb of free space. I'm using Windows 7 64bit. I ran the intel SSD toolbox's 'full diagnostic scan' and it found no issues. I have 1 game installed on the drive, and I'm loading more slowly than most, which is also weird.

What else can be affecting my drive performance?

 

[Idontcare]

Hi

I've been having the same problem again, and was wondering if anyone could be of aid. I have the same set-up, a Intel X-25m G2 80gb as my system drive and an additional X-25m G1 80gb as a game drive.

The odd thing is the system drive seems rather slow. I am getting a '5.9' windows performance index on the drive. I have 21gb of free space. I'm using Windows 7 64bit. I ran the intel SSD toolbox's 'full diagnostic scan' and it found no issues. I have 1 game installed on the drive, and I'm loading more slowly than most, which is also weird.

What else can be affecting my drive performance?

Anything that might be triggering more error-correction efforts will slow down the system, bad cables, poorly plugged in cables (both the sata and PSU kinds).

Likewise an ailing PSU could be a problem, ram might be an issue (does it pass memtest86+?) or you could have a G2 that is starting to have controller failures of some kind.

What you have is a symptom, "Dr I have a cough" e.g. apparent slow loading from drives, but what you lack is a diagnosis, "you have pneumonia" e.g. your ram is dying, etc.

To diagnose the symptom you need data.

 

[Reven]

Idontcare:

What data\tests do you want?

I doubt the PSU is a problem as its a 2 year old Thermaltake Toughpower 750wt. Its overkill for my system, so even if its lost performance it should be enough. If there is a 'psu test' I'd be happy to do it though.

I am currently burning a memtest CD and will have it run sometime tonight. I do doubt its the RAM as nothing is unstable, my game Company of Heroes just loads slower than it used to.

I'll check the cables. Should I just swap my SATA or power cable for a spare I have?

Thanks

 

[sub.mesa]

This trick only works if you never write to the reserved space. This will not work if you already use a partition with free space; the filesystem will eventually write to all sectors and without TRIM ability they won't be 'given back' to the SSD when the filesystem doesn't use those blocks anymore; as happens when you delete a file and TRIM is working.

Even with TRIM it may benefit having dedicated spare space, to avoid having too much fragmentation in the available spare space; scattered snippets of free space TRIMed and given back won't be that useful to the SSD; ideally we want whole free erase blocks.

To give dedicated space to your SSD :
1. perform a secure erase on the SSD (not necessary if it's BRAND new out of the box)
2. partition your SSD leaving some space unused/unpartitioned/unutilized; this will prevent the OS from EVER writing to this LBA location; causing it to never be 'claimed' by the filesystem and thus the SSD will use it as spare space.

The Secure Erase can be done by several utilities, HDDErase.exe with DOS boot environment is the most common; but there are easier methods.

This procedure might benefit the Intel SSDs the most, since these have very little spare space (6.8&#37 to begin with, and have no aggressive garbage collection making the loss of TRIM extra severe to performance degradation over a period of time. I recommend a 25% on top of the 6.8%; which is about 30% total spare space. So 40GB Intel means 30GB partition on it, 80GB Intel means 60GB partition on it. When using RAID0, the same applies; two 80GB = 160GB so make a 120GB partition; the last 20GB of each 80GB won't be partitioned/written to in that case.

 

[Reven]

Can you think of anything I can do without performing a secure erase? I dont want to reinstall everything...

I understand why having extra spare area is important, but wasn't intel supposed to have provided provisions for this? I thought Anand had pushed the drive through some tests and that the G2 drives were pretty resilient.

In addition, I remember in a review Anand stated that even if a G1 drive (with no TRIM) went through the torture test, it'd still feel faster than a HDD. Right now it feels as if I am using a normal HDD for gaming and boot times. The OS works great, but loading is bad. Its almost as if random reads/writes are fine, but sequential performance has weakened.

 

[sub.mesa]

Well i can recommend you install freshly, using overprovisioning to stop rapid degradation of performance on your Intel G1 SSD. This SSD is still quite good; newer SSDs won't really beat it by any decent margin in terms of random I/O performance with realistic data (not writing zeroes to the Sandforce compression engine, in particular ;-) ).

By installing fresh, you can secure erase the SSD and reset the performance level to factory conditions, implement the spare space procedure using partitioning (just using the Windows 7 setup; not using some third-party application) and re-install your apps.

Most games wouldn't need reinstallation; but you should reinstall all regular apps rather than copying their directories over. You can implement some method using 'snapshots' like ghost images, but take special care that you don't end up with a misaligned partition using these utilities.

I understand this is some work though; but your Intel SSD would work much faster in this configuration than leaving it as is; it would also enhance the lifetime/endurance of the SSD a little.

 

[Reven]

OK. Just so we are clear: it is the intel g2 that is degrading. I recently did a secure erase on my g1 and it is working beautifully. When I said my game was loading slowly I was referring tk company of heroes, the only game on my g2 (os) drive.