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======================== VRAMDIR 1.07 for Microsoft Windows 95 ======================== Copyright 1996 Virtual Software Corporation 15016 SE 63 St. Bellevue, WA 98006-4634 http://accessone.com/~virtual/vramdir.htm virtual@accessone.com VRAMDIR is a dynamic 32-bit virtual RAM file system driver for Windows 95. A. Introduction B. Advantages of VRAMDIR over Hard-disks C. Advantages of VRAMDIR over RAM-disks D. Advantages of VRAMDIR over Disk-Cache E. Installation F. Usage G. Benchmarks H. Where to Get the FREE Trial Version of VRAMDIR I. Limit of the Trial Version J. How to Order VRAMDIR K. Technical Support L. License and Disclaimer ============ A. Introduction ============ VRAMDIR is a dynamic 32-bit virtual RAM file system driver for Windows 95. It is to replace RAM-disk and speed up hard-disk related operations. VRAMDIR is over 30 times faster than hard- disks, 5 times faster than RAM-disks, and 2 times faster than disk-cache. VRAMDIR also keeps hard-disks less fragmented, saves hard-disk wears and tears, and saves battery power on notebook computers. VRAMDIR does not pre-allocate any memory, and it has no practical limit on the amount of files it can hold. No matter how much RAM your system has, VRAMDIR puts it into more efficient use and speeds up the system. If the system has more than 32MB RAM, VRAMDIR prevents the RAM from being wasted; if the system has less than 16MB RAM, it is important to use VRAMDIR to increase system speed. ===================================== B. Advantages of VRAMDIR over Hard-disks ===================================== VRAMDIR is tens and thousands of times faster than hard-disks. VRAMDIR creates file systems in Random Access Memory (RAM) to simulate hard-disks. In access time, RAM is thousands of times faster than hard- disks. Locating an address in RAM takes 50-100ns, while seeking to a sector on a hard-disk takes 5-20ms. So RAM access is about 100,000 times faster. In throughput, RAM is tens of times faster than hard-disk. Reading/writing one block of data in RAM is about 20-100MB/s, while on hard-disks it is 1-2MB/s. So RAM throughput is 10-100 times faster. By using VRAMDIR file systems, file operations are tens and thousands of times faster than hard-disks. VRAMDIR keeps the hard-disks less fragmented. Without VRAMDIR, temporary files scatter around on hard-disks. This can be prevented by creating the temporary files in VRAMDIR. Less fragmented hard-disks result in faster hard-disk access. VRAMDIR saves wears and tears of hard-disks. Hard-disks have mechanical parts and thus have much shorter life-spans than RAM. When accessing files in VRAMDIR, hard-disks are not accessed. Thus hard-disks are less probable to fail, and hard- disks live longer, hence it is less likely to lose your data on hard-disks. VRAMDIR saves battery power on notebook computers. When hard- disks are less often accessed because of VRAMDIR, less power is consumed by hard-disks, and the battery runs longer. ============================================= C. Advantages of VRAMDIR over RAM-Disk Utilities ============================================= VRAMDIR is several times faster than RAM-disk utilities. VRAMDIR is a 32-bit protected-mode Windows 95 native virtual device driver (VxD), while RAM-disk utilities are 16-bit real- mode DOS device drivers. With RAM-disks, Windows 95 needs to switch forth and back between 16-bit real-mode and 32-bit protected-mode. This very time consuming mode switching is avoided in VRAMDIR. For example, when benchmarked against RAMDRIVE, VRAMDIR is more than 4 times faster. VRAMDIR is dynamic. When there is no file in VRAMDIR, VRAMDIR does not allocate any memory. RAM-disks, on the other hand, pre-allocate fixed amount of memory. Even when the memory is not used by files on a RAM-disk, the memory is no longer available to system and application programs. With VRAMDIR, no extra memory is taken, more memory is available to the system, and the system runs faster. When more files need to be on RAM-disk than the fixed amount pre-allocated, RAM-disk is not able to hold them. The operation will fail, and your application or even the system may crash as a result. With VRAMDIR, it expands on demand. There is no practical limit on the number of files and the size of files that can fit into VRAMDIR. (The limit is the total amount of physical memory plus the free hard-disk space in your system, which is even larger than what is available without VRAMDIR, the free hard-disk space alone.) VRAMDIR is virtual. VRAMDIR can return memory back to the system, while RAM-disks can never do that. When other applications need more memory, files in VRAMDIR can be saved onto hard-disks and memory is returned to system. You never need to worry about VRAMDIR using too much memory. VRAMDIR makes sure that it always puts memory into the best use and that the system runs as fast as possible. VRAMDIR creates virtual file systems, while RAM-disks create disk images on which to build FAT file systems. Disks are block devices and have limitations. For example, on a disk even when only 1-byte is used in a block, the rest is not available to other files. RAM is different from disks. It is not efficient to use RAM in the same block manner as disks. FAT file system has further limitations. In RAM-disks, e.g., space needs to be pre-allocated for File Allocation Tables (FAT), the block size and the number of entries in the root directory, etc., needs to be pre-determined. VRAMDIR avoids the limitations of block devices and the FAT system. VRAMDIRÆs file system is virtual and much more efficient. There is no setting needs to be fine-tuned. VRAMDIR maps directories into RAM, while RAM-disks create new drives. With VRAMDIR, it is easy to map existing directories, e.g., TEMP directories, into RAM. There is no new drive letter to worry about. Existing settings for the system and applications do not need to be changed to point to the new drive letter. VRAMDIR is very easy to set up, and the system runs exactly like before, except that with VRAMDIR it will be much faster. VRAMDIR supports Long File Name, while RAM-disks only support short name. =============================================== D. Advantages of VRAMDIR over Disk-Cache Utilities =============================================== VRAMDIR is several times faster than disk-cache utilities. VRAMDIR is not designed to replace disk-cache, but VRAMDIR does something that disk-cache can not do. Disk cache cannot replace VRAMDIR. They are used for different purposes. Disk-cache keeps most recently accessed files in memory. You do not have control of what to keep in the cache and what not. VRAMDIR let you control what to be put in RAM. VRAMDIR is designed to speed up temporary file access. VRAMDIR is much faster than disk-cache in the best circumstances. Many applications create temporary files on hard-disks. With disk-cache, when a temporary file is created, it will stay in memory for a short while. Then within, e.g., 1 second, disk cache will write the file out to hard-disks, which is very slow. With VRAMDIR, files can stay in memory much longer. A temporary file may stay in memory during its entire existence, from the point it is created, to the point it is deleted. Hard-disks may never need to be accessed in these temporary file operations. VRAMDIR is still several times faster than disk-cache overall, even in the worst situations. For example, WINBENCHÆs disk/mix test, which emulates popular applicationsÆ disk operations, reads/writes over 100MB of files. When the test is run on a Pentium 100 with 32MB RAM, VRAMDIR needs to swap a lot of data to the disk. This is one of the worst scenario for VRAMDIR. But running the test on VRAMDIR is still over 2 times faster than VCACHE. ============ E. Installation ============ If applicable, Unzip VRAM107T.ZIP or VRAMD107.ZIP into a directory, e.g., C:\VRAMDIR Switch to the directory, e.g., C:, CD C:\VRAMDIR In Windows 95, run INSTALL.BAT. This copies files into the Windows system directory and modifies system settings. It automatically sets the directories pointed to by the TEMP and TMP environment variables to be handled by VRAMDIR. After Windows restarts, all newly created files and sub- directories under the TEMP directories will be in RAM. Previously existing files and directories will still be on the hard-disks. You can run the control panel VRAMDIR configuration utility to change the list of directories to be handled by VRAMDIR. If you want to temporarily disable VRAMDIR, you can remove all the directories in the list using the VRAMDIR configuration utility in control panel. If you want to completely uninstall VRAMDIR, you can run Control Panel - Add/Remove Programs - Install/Uninstall, select VRAMDIR, then press Add/Remove. ===== F. Usage ===== IMPORTANT: Any files under VRAMDIR will be deleted after Windows is shut down or restarted. So only temporary files should be put under VRAMDIR. If you put other files in VRAMDIR for faster operations on them, remember to move them out to non-VRAMDIR directories after you finish working with them, if you want to save them on the hard-disk. When VRAMDIR is first installed, it will automatically put TEMP and TMP directories under VRAMDIR. You can later use VRAMDIR configuration utility in control panel to edit the list. When you delete VRAMDIR files in Windows Explorer, if you say YES to put the files into Recycle Bin, the files will be written onto disk in Recycle Bin, which can be slow. If this is not what you want, you can delete the files without saving them into Recycle Bin by holding down the SHIFT key when you press DELETE in Windows Explorer. If an application queries for the amount of free space in a VRAMDIR directory, the free space of the hard-disk that host the directory is returned. If the application complains about not enough space, more space on the hard-disk need to be freed. Most likely, VRAMDIR does not need the free space on the hard-disk, and VRAMDIR is able to hold more files than what the hard-disk free space indicates. For example, if the hard-disk has 10MB free, after 5MB of new files are created in VRAMDIR, the hard-disk may still have 10MB free, instead of 5MB. Directories mapped to VRAMDIR can not be deleted or renamed. For example, if C:\WIN95\TEMP is mapped to VRAMDIR, C:\WIN95 can not be deleted, nor can it be renamed, e.g., to C:\WINDOWS. If you want to delete or rename such directories, you should unmap the VRAMDIR directory first, e.g., unmap C:\WIN95\TEMP in the control panel VRAMDIR configuration utility. You can get VRAMDIR performance statistics from System Monitor: VRAMDIR - Memory Allocated: the total amount of virtual memory allocated by VRAMDIR at the moment. VRAMDIR - Bytes Read/Written: the total number of bytes read/written in VRAMDIR from system boot-up. VRAMDIR - Operations Performed: the total number of file operations performed by VRAMDIR. ========== G. Benchmarks ========== Wintune 95, WINDOWS Magazine's test and tune-up kit, http://www.winmag.com/software/wt95.htm WinBench 96, PC Magazine, http://www.zdnet.com/zdbop/winbench/winbench.html MDB95, http://ourworld.compuserve.com/homepages/mschoebel/mdb95.htm To test VRAMDIR speed with these benchmarks, you need to map a root directory to VRAMDIR, e.g., D:\. You should select a drive with the fewest files. Remember to remove the mapping after you finish benchmarking. Otherwise, all new files on that drive will be in RAM and will not be saved onto the hard- disk. For the true speed of hard-disks, you need to look at the uncached benchmark number in MDB or Wintune. To get the true speed of VRAMDIR, you need 3MB free memory to run Wintune, or enough free memory to hold the test file in MDB. Before you run the benchmarks, you can check the amount of free memory using System Monitor. To make more free memory available, you can limit VCACHE size by putting the following in SYSTEM.INI, e.g.: [vcache] MinFileCache = 1000 MaxFileCache = 1000 You can remove these settings after you finish benchmarking. To get the real life speed difference between VRAMDIR and cached hard-disks, you can run the Disk WinMark in WinBench, which emulates disk file operations in 13 popular Windows applications. For example, the results of the benchmarks on a Gateway 2000 Pentium 100: MDB 16MB file: Hard-disk: 1.4 MB/s RAMDRIVE: 9.0 MB/s VRAMDIR: 35.0 MB/s WinBench Disk WinMark: VCACHE: 0.7 MB/s VRAMDIR: 1.5 MB/s ============================================== H. Where to Get the FREE Trial Version of VRAMDIR ============================================== http://accessone.com/~virtual/vramdir.htm ========================== I. Limit of the Trial Version ========================== If you have not paid Virtual Software Corporation for VRAMDIR, you are running a trial version of VRAMDIR. After you experienced the advantages provided by VRAMDIR, you can order the full version from Virtual Software Corporation. The trial version is time limited to 30 minutes. After 30 minutes, the files will be written to hard-disks instead of in VRAMDIR. The system will function as before. If you need more time to evaluate VRAMDIR, you can restart Windows and VRAMDIR will run for another 30-minute. If you buy the full version, there will be no time limit, and VRAMDIR will function all the time. After 30 minutes, a message box will pop up signaling the expiration of the trial period. If the display is blanked into power-saving mode when the message box pop up, the message box will not be visible. Just press SPACE to get rid of the invisible message box. In the trial version, sub-directories under VRAMDIR are created on the hard-disks, while files under VRAMDIR are in RAM. If you buy the full version, all files and sub- directories under VRAMDIR will be in RAM. The full version is a little bit faster than the trial version. ==================== J. How to Order VRAMDIR ==================== If you have an email account, we can send you a UUENCODED VRAMD107.ZIP file through email. It costs US$10. Fill and print out ORDER.TXT form and send it to us with a check of US$10. Please make sure to include your email address. If you prefer to receive a floppy disk, it costs US$15 for an address in US, and US$20 for outside US. Fill and print out ORDER.TXT form and send it to us with fund in US$. You can send the check and the order form to: Virtual Software Corporation 15016 SE 63 St. Bellevue, WA 98006-4634 USA ================= K. Technical Support ================= You can visit our www site at: http://accessone.com/~virtual/vramdir.htm If you have further questions, you can send us email to: virtual@accessone.com You can also send us postal mail to: Virtual Software Corporation 15016 SE 63 St. Bellevue, WA 98006-4634 USA ====================== L. License and Disclaimer ====================== One copy of VRAMDIR can only be installed on one workstation computer. It can NOT be put on network servers to be shared by workstations. The full version of VRAMDIR can NOT be distributed or copied to any other people in any way. Anyone distributing the trial version of VRAMDIR must first contact Virtual Software Corporation for authorization. Users of VRAMDIR must accept this disclaimer of warranty: VRAMDIR is supplied as is. The author disclaims all warranties, expressed or implied, including, without limitation, the warranties of merchantability and of fitness for any purpose. The author assumes no liability for damages, direct or consequential, which may result from the use of VRAMDIR.