Does anyone use a dedicated HD to run PS ?
Scratch disk for PS
Does anyone use a dedicated HD to run PS ?
I use a scratch disk for PS, but that is different from running PS on a separate HD.
I put the scratch disk on a separate internal drive that has 167G of free space.
If you're running Windows XP I know it's best to pick a separate drive from the drive/partition that windows uses for it's virtual memory. The separate drive could be internal or external, depending on your setup. I'm not sure if the same advice holds true for Vistas or Windows 7.
If you're trying to speed up PS, I can give you more tips, but I need to know what version of PS you're using and what OS as well.
Ok what a about CS4 and Mac OS 10.6 I have my scratch disk setup on a seperate Internal drive. Thanks Mike KOriginally Posted by Jeff Donald
I think it's best to assign the scratch disk to a separate drive, regardless of operating system or version of Photoshop. See this note from Adobe:
http://help.adobe.com/en_US/Photosho...b64-7489a.html
I recently incured a "meltdown" of several programs. While researching how to completely remove CS3 before reinstalling PS a website suggested installing a separate hard drive as a scratch disk. My computer is less than a year old and runs multiple programs at a pretty good clip. I figured since I have plenty of expansion bays available and drives are cheap I would do it if I can notice a real world difference.
OS is Vista with 8 GB ram.
Thanks for your replies to date.
The speed of PS can be improved with a few simple tweaks in the Preferences.
One of the biggest improvements will be increasing the RAM PS can access. If you have 4 GB or more system Ram I would suggest setting memory usage to 70 to 75%. With 8 GB might try even higher settings such as 80 to 85%. If PS or the OS starts to act sluggish then back it down.
Set up the Scratch Disk so that only PS has access to a large portion of the disk. It should be a separate drive that does not have the OS or PS on it. It could be partitioned and part of the drive could be used for storage etc.
Reduce the number of history states from the default setting of 20 to 10 or 15. This reduces the number of undos you can perform, but 20 History States really slows down PS.
If you work on large files with few layers set the Cache Levels higher such as 6 to 8. If you work on smaller files with more layers, set the Cache Level lower such as 1 to 3.
PS's clipboard uses a lot of Ram. You can purge the clipboard by going to Edit>Purge to free up Ram.
Close unnecessary programs you may have running. Even program that are idle consume CPU cycles and Ram.
PC users can gain some benefit by defragmenting their drives. Mac OS X defrags and the fly and little speed benefit is gained by defragmenting a Mac. Don't waste time defragmenting the Scratch Disk, the PS files are only temps and are trashed when PS is quit.
There are some other speed benefits to be gained with CS4 because it is capable of using the graphics card (if it's fast enough) to do some operations. There are some other tips regarding fonts, brushes, actions etc. but they are more specific to how and what type of work the user is doing.
The last tip is to make sure your running the latest version. Adobe updates to PS are usually related to performance glitches and it is best to update. The latest version of PS CS4 is 11.0.1
Do you gain anything by using an external drive for the scratch disk, or does it need to be an internal drive only?
In order of speed wound be an eSata I/II drive (either internal or external), FireWire 800, FireWire 400, and lastly USB2. You gain speed even with a slower external drive, because without a Scratch Drive PS will use the internal drive with the application and OS on it. This will slow down not only PS, but the OS will seem slower as well.
Jeff,
While I have agreed with everything you've said up to now, I don't agree that slower external drives like USB will still speed up photoshop. An internal drive is very fast and if the computer is not doing a lot of other stuff, it shouldn't be paging, so photoshop writing to a scratch file on the main disk that contains the operating system will not be impacted much and still operate nice and speedy.
One key when working on large files is to close other programs unless really needed, before starting photoshop to free up as much ram as possible. I often work on multi gigabyte image files and set photoshop to use 90% of ram.
Roger
More tips for optimizing performance. These are for CS3 on a Mac, but most apply to CS4 and to Windows systems.
Use this link and pick window or Mac and also choice of CS.
http://www.adobe.com/cfusion/search/...20&cat=support
Bill
Those are all great suggestions for CS3. However, some issues have been addressed in CS4, such as large tiles. If you use a lot of fonts you may not want to disable the WYSIWYG font preview.
Another speedup I forgot to mention is not launching Bridge automatically when you start PS. Launching Bridge slows down the startup considerably and uses valuable Ram.
It depends on several factors. Many people are editing on notebooks that utilize slower RPM drives. Most external drives are 7200 RPM (except the very compact drives) and even though on the slower USB 2 buss, they'll speed up PS to some degree, though not as much as the eSata and FireWire drives.
Of course if you're really after speed, your scratch disk will be a RAID 0 set-up using 10K or 15K drives.
Jeff,
I agree on depends on several factors. But citing rpm as an indicator of real throughput is like citing megapixels as an indication of image quality. There are many things that affect actual throughput. For example, a higher capacity drive has information packed smaller so a slower rotational rate can still deliver a high speed data stream.
It is relatively simple for people to get an indication of how effective a particular drive will be, whether internal system drive or external USB. Time how long it takes to copy a big file to the same drive. Use a file that is significantly larger than the amount of memory you have. For example, if you have 8 gigs of ram use a file that is 20 to 50 gigs. Copy the file to the drive to be tested. Then time copying the file to the same drive. I bet you'll find then pretty much any internal drive will do better than any USB drive. Test each drive you have and set photoshop to use the fastest drive for scratch (or multiple drives).
Roger
Roger, sorry for the confusion. It is just my experience that any scratch drive is better than having the same drive the application and the OS are on, as the scratch drive. It is particularly bad with Windows, because the virtual memory allocation that Windows uses can interfere with Photoshop. My students that don't have separate scratch drives frequently get Virtual Memory Low on their Windows systems. This may have changed under Windows 7, but was particuarly bad under XP Home and Vista. Nothing quite slows down the workflow like a system warning.
If you’re really going after speed, you want a 64-bit system, as much RAM as you can put in it and a Solid State disk. End of story.
Hitting the disk, any disk, even a solid-state disk, is bad for performance.
While a 15K SAS disks sound cool, they couldn't be further from it. They’re an order of magnitude slower than an SSD, a lot louder and much hotter. I had a 15K Cheetah in my workstation some time ago. Its high-pitched whine was amazingly loud and annoying and it got hot enough to cook and egg on even with a fan blowing over it. I would never repeat the experience, especially now when SSDs are faster, cooler, more reliable and absolutely silent. 15K drives belong in soundproofed climate-controlled data-centers, where they won’t cook themselves and can’t be heard, not studios and offices.
I wouldn’t bother with RAID either, not RAID-0 and not for a scratch disk. It’s just adds more complexity and latency, neither of which you really want or need. Again, if you have enough RAM, you shouldn’t have to hit the disk at all. Windows will cache the scratch file so long as you give it room to do so.
The only possible way you could be running into the issue you seem to be describing is if Windows was configured to use a fixed size page file and it was running out. Windows will not over commit its backing store (no OS should although AFAIK Linux does) meaning you need space on your drive to back every page that's held in memory be it in the page file or in the file it was loaded from.
As long as you have enough free disk space for the page file to grow when it needs to and you let the system manage it's size, there is no way that moving the PS scratch file will change anything.
If you just Google Photoshop Windows Low Memory Allocation you'll see thousands of posts, complaints, etc. In the real world, I have students experiencing it weekly. So it seems very possible and likely. You've got to remember that many people run PS on older OS's, minimum amounts of Ram, and have only one system drive and it may be 70% full or more. Any easy way to speed up the performance is to use another disk as the PS Scratch Disk. It is even likely they may have an old drive laying around that could be installed and used. This is a low cost alternative, to adding more Ram.The only possible way you could be running into the issue you seem to be describing is if Windows was configured to use a fixed size page file and it was running out. Windows will not over commit its backing store (no OS should although AFAIK Linux does) meaning you need space on your drive to back every page that's held in memory be it in the page file or in the file it was loaded from.
As long as you have enough free disk space for the page file to grow when it needs to and you let the system manage its size, there is no way that moving the PS scratch file will change anything.
The whole idea of a Scratch Disk is to improve performance. RAID 0 (striped pair) is fast, low cost (user may have two drives he can pair or just add one drive), simple to setup and operate. The data on a scratch disk is less critical and does not require the redundancy of a more complex RAID system. I've used two SATA drives striped RAID 0 for my personal system for over 4 years with no issues what so ever. The original pair I just replace several weeks ago to add more space to the system. I've also used RAID 0 systems on other editing systems in a production environment and I can report no issues in those installations as well.I wouldn’t bother with RAID either, not RAID-0 and not for a scratch disk. It’s just adds more complexity and latency, neither of which you really want or need. Again, if you have enough RAM, you shouldn’t have to hit the disk at all
Depending on the type of memory used in the SSD, the low cost MLC flash memory used in most lower cost SSD's has a limited number of read/write cycles, about 10,0000 cycles. This would not last very long in a Scratch Disk application and several companies are saying SSD is a poor choice for Virtual Memory use. You can use SLC flash memory and improve the life from 10,000 cycles to 100,000 cycles, but the cost has doubled. I can buy two 1 GB drives and configure as a RAID 0 for under $150. A 160 GB SSD with SLC flash memory is about $275. It has 12.5X less space and is almost twice as expensive.If you’re really going after speed, you want a 64-bit system, as much RAM as you can put in it and a Solid State disk. End of story.
More memory is always the easiest and fastest way to better performance overall. However, many people (most?) may have systems with limited Ram expandability. They may have even already maxed their Ram at 2 GB or 4 GB. For those users, a scratch disk will improve performance and can be fairly cost effective.
Last edited by Jeff Donald; 01-03-2010 at 02:53 AM. Reason: spelling
Sorry, in my haste I forgot about address space exhaustion yielding an OOM error. Ironically, too, since the only OOM error I’ve ever had in PS was due to this. The triggering criteria was having too many history states in a large document.
However, moving the scratch disk will do even less in this case than the other one. The only way to remove the problem is to give PS more address space (can’t be done when the program is running) or freeing allocated memory. I seem to recall resolving my issue by clearing the history and reducing the number of history states.
Either way, if you’re seeing errors daily there’s almost certainly something misconfigured or your whole system is sub-optimal to the point of being broken.
If they want to improve performance, they should be adding RAM and as much as their hardware and OS can support. The situation you’re outlining, moving the scratch file instead of adding ram, akin to bailing a sinking boat with a bucket instead of turning on the bilge pump.You've got to remember that many people run PS on older OS's, minimum amounts of Ram…
What part of those 15K SAS disks were low cost?An easy way to speed up the performance is to use another disk as the PS Scratch Disk. It is even likely they may have an old drive laying around that could be installed and used. This is a low cost alternative, to adding more Ram.
Moreover, using an old disk for your scratch file is likely a huge waste of time. At best, it might be imperceptibly faster, at worst it’ll be slower because it’s old and just not fast. Second, since you’re still not addressing the lack of RAM you’re still going to page just like before and that’s going to keep performance in the same ballpark.
Maybe you can understand my confusion; you seem to be suggesting one spends time or money to do something that will have comparatively no benefit. For the $100, you can get the fastest current 1TB SATA disk but you’ll still page and do so at 60-110MB/s. Put the same money into RAM and you can get 4GB, enough to stop or greatly reduce paging and keep your data moving around at at 1000s of MB/s.
Not really, the scratch disk exists so Photoshop can work with datasets larger than 2GiB. Without it, you would simply not be able to work with multiple or large files at all. The side effect of being able to page out inactive data freeing usable space is a nice side effect but hardly the whole idea behind the scratch disk.The whole idea of a Scratch Disk is to improve performance.
I never said that you should use a more complex RAID level for your scratch disk. Actually, I said exactly the opposite. The benefit of using RAID at all, unless you have other reasons for the array, is marginal at best.The data on a scratch disk is less critical and does not require the redundancy of a more complex RAID system.
I doubt that, but I don’t have any actual evident to disprove it.More memory is always the easiest and fastest way to better performance overall. However, many people (most?) may have systems with limited Ram expandability.
I think you missed my third post above, where I suggested adding Ram as the first step to increasing performance in PS. Some users try to get the very last bit of performance out of their systems. In such cases, having a fast Scratch disk can improve performance, but this is only after adding ram up to the system limit. A RAID 0 scratch disk is almost twice as fast as a single disk. I can personally attest that this will speed up the performance of Photoshop CS4. I have used a RAID 0 configuration on my own personal editing station since 2005. I've been using RAIDs since 1993 for video editing.
The suggestion of adding fast disks, such as the 10K and 15K disks mentioned above, was more for the ultimate setup and not for the average PS user. The 15K suggestion was not meant as a cheap solution, but a performance solution. You could compare this to the car enthusiast that spends $4K to $6K to get a wheel set that is 4 or 5 pounds lighter. It will aid performance and handling, but it is not the ultimate speed enhancement.
You seem to be under the impression that all RAIDS are complex and involve redundancy. RAID O is a very simple and easy RAID. It has not redundancy and I would not call it complex. Both the Mac and PC OS have free tools to create various types of RAIDs and it is easy to install the drives in most systems and also easy to configure. I'm not sure where your impression that all RAIDs are complex, have redundancy and latency. Here is a good link for learning about RAIDs.
I think our discussion should head towards Private Messages as this is way off the topic of the original posters question.
Last edited by Jeff Donald; 01-04-2010 at 12:44 PM. Reason: spelling
Let's see if I understand?
I have activated the scratch disk on PS, even though I only have a hard drive on my machine, it is a disk with lots of gigabytes but I would like to know if I am gaining anything by doing that.
Thanks for your help.
JC
There is no gain if it is the same drive, even if the drive is partitioned. The gain is from using a totally separate drive, a second drive. The heads that read the data on a drive can only move so fast. If there are a lot if requests for date (read/write activity) the data will transfer off the single drive slower. If the drive is separate, the data can come off the scratch drive at full speed, while the drive with the OS and program can do what it needs to do faster, because it is not bogged down by all the scratch disk activity.
Well, you don't really activate a scratch disk. Photoshop always has an active scratch disk. It defaults to the same drive that the OS is on unless you specify a different disk.
And, as Jeff said, you can gain speed only by putting the scratch disk on a separate drive from the OS. That allows both disks to run simultaneously: While the OS disk is handling page files, the other disk can be running as the scratch disk.
Thank you Jeff and David for your help, now it makes sense. It sounds like I will have to get a new HD.:o
Without a doubt a separate disc is the way to go for scratch, but if you only have one then set up a partition for scratch only. If you do PS will not always have to hunt for a place to scratch in case something else writes all over the place which will happen.....
Bill
Having a separate partition will not speed up PS. However, it will aid in preventing fragmented disks and you wont have to defrag the disk as often.
Thank you so much Jeff.
I will be buying a new HD for that purpose soon.
JC
While technically this is true it sure can keep PS from slowing down. So in some sort of reality it helps.
Bill
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