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shady28

Solid state disk drives

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Besides the platypus link that was posted, where's the site that offers 320 MB of SSD @ a cost of $4000?

RAMDISK ROCKS!!!. It's just too bad that I can't fit more of it into my system. (Yah....a 12 GB RAMDISK would have been cool, but rather a little useless for my system since I can't really read/write/compress that fast anyways.)

P.S. I've benchmarked my 110 MB RAMDISK before with ATTO, and I can say....that most people would be crapping themselves when you see the scores (i.e. 400 MB/s read AND write). Now of course there'd be those that would question the benchmarking method, and I'd TOTALLY agree with you. But then again, most people here are familar with the scores that we're used to seeing from ATTO and for people to even come CLOSE to 200 MB/s, they have to have some kind of RAID setup (typically a RAID0) setup.

Down side to RAMDISK....it's RAM...so...the info doesn't stay there long. It's an interesting thing and the idea of having it individually powered is nice, but it won't really work with RAM. What I WOULD probably like to see is to have it so that it is an independent slot (similar to the memory card idea for the S2603 Dual Xeon board, with the 8 DIMM slots). The only difference is that it functions separately from the main RAM, BUT, uses off the shelf RAM components. An added bonus would be for it to boot off the second "memory card". *sigh*....it's nice to dream...

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Indeed, you have successfully made the argument that a ram based SSD is faster than a magnetic disk, but it remains much slower than system ram.

Your point about committing to disk is a valid one, and is an example of the type of legacy consideration I mentioned above.  In such a case, a simple driver can be used to create a ramdisk from system ram.  I have used ramdisks under w2k for large platform builder(win ce) compiles, and the improvement is dramatic on SMP machines.

What has not been presented is an argument to use a slow, expensive, external SSD over traditional system ram.

It is true, that modern x86 processors are limited to 36 address lines, and may only address 64GB of space.  It is also true, that motherboards equipped with chipsets that actually accommodate 64GB of ram, are expensive.  

That said, these factors should be considered in context.  For less than the price of a 4GB SSD, I can build an entire quad processor system equipped with 12GB of RAM.  While this approach does limit you to a 64GB ‘disk’, I suspect the market share of > 60GB SSDs in miniscule.

If 64GB is really not enough, Hammer is right around the corner.

System RAM is always volatile. Perhaps I'm just an old-fashioned tech, but it'd be a cold day in Hades before I'd put my DB transaction logs on volatile memory, even if I had a UPS.

As for an argument about using "slow, expensive, external SSD over traditional system ram", I thought that I had made my point about SSDs, in my opinion, being justified for certain I/O bound business processes, usually involving a SQL DB or some such, where the amount of I/Os going through your server actually impacts your corporate bottom line (ie, limits your business earning potential) or where downtime (as in the RAID example I gave) costs are so prohibitive that an SSD is justified to minimize system vulnerability.

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System RAM is always volatile.

RAM is volatile.

Contemporary SSDs with the capacities and performance being discussed, use RAM.

System RAM is no more fundamentally volatile than the RAM in a Solid State Disk.

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interesting topic :D although some aggressive answers can be read :x

I think there are several reasons to think about a SSD;

1) Speed. Those people will probably have to pay for expensive solutions.

2) Industrial. They want to avoid mechanical movement and will also pay

3) Diskless. For instance Internet routers/firewalls.

4) Silent. After we're able to have fanless CPU's and power supplies, the only remaining 'noise' is the hard disk.

Personally I'm looking for option 4, how to create a 100% silent PC :P . I haven't found a real solution for that yet.

Wykat

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Guest russofris
interesting topic  :D although some aggressive answers can be read  :x  

I think there are several reasons to think about a SSD;

1) Speed. Those people will probably have to pay for expensive solutions.

It is agreed upon that ramdisks are faster than SSDD's

2) Industrial. They want to avoid mechanical movement and will also pay

Ramdisks have no moving parts. You can boot the PC from a LAN.

3) Diskless. For instance Internet routers/firewalls.

See above. The computer in my rocket boots from a CD Rom, which dumps info to a ramdisk, and then detaches from the system. Sorta like jump starting a car.

4) Silent. After we're able to have fanless CPU's and power supplies, the only remaining 'noise' is the hard disk.

See all of the above answers

Personally I'm looking for option 4, how to create a 100% silent PC  :P . I haven't found a real solution for that yet.

Wykat

Apple IIe or put it in another room and use a KVM extender?

Here's where I'm disappointed. I keep hearing the same arguments. SSD is fast, SSD has no access time, SSD has no moving parts. The only benefits of SSD over system ram are that it can be made nonvoltile and be larger than what availble ram PC's can store. Period, end of story. That's it. Thats all. Roll the presses. Finito!!! If you have an application that demands those two factors, then by all means, get a SSD.

Thank you for your time,

Frank Russo

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Wykat,

No single device that I am aware of will provide all four of the listed benefits, at a meaningful capacity.

If the SSD is very fast, it is based on RAM, and will typically use magnetic disks to preserve state. The performance figures quoted by Shady are from these types of SSDs. As I have clearly described above, I feel that in the vast majority of cases, users are better served by a driver based ramdisk.

If it is based on flash, it will be rather slow (~3MB/s), but will be silent, tolerate vibration, and so forth.

I would add that increasingly, flash is cheaper than disks in some applications. For example, a router will happily boot from a $30 CF card. $30 drives are pretty hard to come by. This is only the beginning of a trend described here.

Ever since my father brought home a GRiD Compass with bubble memory, I have been promised that solid state devices would replace magnetic disks. I am still waiting.

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I should add that while faster, multi-channel flash SSDs are certainly possible, I am aware of none that approach the speed of even a commodity motherboard’s local ram interface.

I have yet to see a 500 channel NAND flash controller.

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cas wrote:

As I have conceded above, an externally powered SSD will probably shave as much as a minute off your reboot time. A BIOS change would allow you to do the same thing with a standard Suspend To Ram motherboard

Suspend to RAM motherboards do not shave a minute off boot time, because you dont reboot when you bring the box back from sleep mode.

As far as the use of a paging or swapfile is concerned, this depends on the operating system you are using, and how it is configured. For example, there is no page file in my system.

And you will be completely screwed if you ever run out of RAM. Unless, of course, you arent doing anything important on your computer.

It would be even better if that person had written ramdisk drivers for multiple operating systems.

If you are working on a project, do you really want to put your changes into volatile RAM?

RAM is volatile.

Contemporary SSDs with the capacities and performance being discussed, use RAM.

System RAM is no more fundamentally volatile than the RAM in a Solid State Disk.

Wrong. Quite a few SSDs use Flash memory. Look here :

http://www.bitmicro.com/products_edsw_specs.html

Flash disk drive, capacity 128MB - 75GB, < .48ms access times (48us), 34 MB/Sec sustained xfer rate, 40MB/sec burst, uses U2W SCSI interface and can be setup in a RAID configuration.

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More..

http://www.business.com/bdcframe.asp?ticke...storage_devices

"The 2.5-inch E-Disk 2A66 and 3.5inch E-Disk 3A66 ATA/UDMA-66 flash drive devices are the first in the industry. These flash drives support PIO Modes 0, 1, 2, 3, and 4 and UDMA Modes 0, 1, 2, 3 and 4. By eliminating seek time, latency and other electro-mechanical delays inherent in conventional hard disk drives (HDD), they have read and write rates of up to 66.6 MB/sec and random access time of less than 0.068 milliseconds.

The UDMA E-Disks are high capacity flash disk drives available in a variety of sizes. The low-profile E-Disks in 2.5-inch HDD footprint are offered with 128 MB minimum capacity under 8.5 mm and up to 17408 MB in 24.9 mm height. The 3.5-inch version comes with maximum capacity of 77824 MB in 50.4 mm height and minimum capacity of 128MB in 13.13 mm height"

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I said an STR motherboard, I didn’t say I would be suspending to ram.

A machine with 1GB of physical memory, and a 1GB SSD backed page file will run out of memory long before a far less expensive system with 4GB of physical ram. It will also be much slower.

Regarding the performance of the drives, I recommend you read the fine print. Their FC and ATA drives are rated from 4.5MB/s – 68MB/s. You wouldn’t tolerate that in a $70 magnetic disk, let alone something as exorbitantly expensive as an SSD.

This is slower than even low end ram based SSDs discussed above, to say nothing of a ramdisk based on system ram.

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Actually, I take back the reference to the FC disk. It turns out that SCSI, FC, and ATA all report considerably different values.

I would love to see some independent tests.

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I use a ramdisk in my liquid hybrid rocket for example.

Your rocket!?!

Perhaps you would consider NOR flash, even embedded flash?

Most interesting.

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See above.  The computer in my rocket boots from a CD Rom, which dumps info to a ramdisk, and then detaches from the system.  Sorta like jump starting a car.

This is exactly what I'm looking for, but I haven't found a solution yet to start W2K this way :( . I would like to take a modern mainboard and add 1.5 GB of RAM. Then via bootmanager create a 1GB RAMdisk, copy an W2K image on it and boot. All data storage goes on the network.

Wykat

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Guest russofris
I use a ramdisk in my liquid hybrid rocket for example.

Your rocket!?!

Perhaps you would consider NOR flash, even embedded flash?

Most interesting.

I would considder it if someone else were willing to pay for it. The computing portion of the rocket has cost me under $1000 so far and is working quite well.

Thank you for your time,

FranK Russo

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Guest russofris
See above.  The computer in my rocket boots from a CD Rom, which dumps info to a ramdisk, and then detaches from the system.  Sorta like jump starting a car.

This is exactly what I'm looking for, but I haven't found a solution yet to start W2K this way :( . I would like to take a modern mainboard and add 1.5 GB of RAM. Then via bootmanager create a 1GB RAMdisk, copy an W2K image on it and boot. All data storage goes on the network.

Wykat

Grab a copy of XP embedded. NT/2K/XP appear to be designed specifically NOT to work in this configuration.

Linux Does work in this configuration, but only if you load DOS first (to set up the drive).

Boot off the CD Into DOS, create the ramdisk (find a better ramdisk.sys then the one in MS-DOS). DC/DD the boot image from the cd to the ramdisk, and Load linux (Don't reboot).

Thank you for your time,

Frank Russo

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System RAM is always volatile.

RAM is volatile.

Contemporary SSDs with the capacities and performance being discussed, use RAM.

System RAM is no more fundamentally volatile than the RAM in a Solid State Disk.

Contemporary SSDs use RAM, but if you purchase a nonvolatile SSD then the memory is powered internally and is safely written to disk in the event of power failure. Nonvolatile SSDs are specifically designed to avoid data loss. Hence the term "nonvolatile". :wink:

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Guest russofris
Contemporary SSDs use RAM, but if you purchase a nonvolatile SSD then the memory is powered internally and is safely written to disk in the event of power failure. Nonvolatile SSDs are specifically designed to avoid data loss. Hence the term "nonvolatile".  :wink:

Please re-read the thread.

Thank you for your time,

Frank Russo

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Not all SSDs are based on RAM..

From :

http://www.bitmicro.com/products_edsw_specs.html

Flash disk drive, capacity 128MB - 75GB, < .48ms access times (48us), 34 MB/Sec sustained xfer rate, 40MB/sec burst, uses U2W SCSI interface and can be setup in a RAID configuration.

And :

"The 2.5-inch E-Disk 2A66 and 3.5inch E-Disk 3A66 ATA/UDMA-66 flash drive devices are the first in the industry. These flash drives support PIO Modes 0, 1, 2, 3, and 4 and UDMA Modes 0, 1, 2, 3 and 4. By eliminating seek time, latency and other electro-mechanical delays inherent in conventional hard disk drives (HDD), they have read and write rates of up to 66.6 MB/sec and random access time of less than 0.068 milliseconds. "

If you look at the specs for various models, you'll find some that have 320Mb/sec transfer rates, all with the <1ms access times. All of these devices are based on Flash memory.

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No. No they are not. As I mentioned above, you can build multichannel flash controllers. In order to approach the memory bandwidth of even commodity motherboards however, hundreds of channels would be needed.

I will stick to my faster less expensive, and faster SDRAM/Disk hybrids, thank you very much.

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Contemporary SSDs use RAM, but if you purchase a nonvolatile SSD then the memory is powered internally and is safely written to disk in the event of power failure. Nonvolatile SSDs are specifically designed to avoid data loss. Hence the term "nonvolatile".  :wink:

Please re-read the thread.

Thank you for your time,

Frank Russo

If you're trying to point out something that you think I missed, why don't you put that in a message, rather than a vague "re-read the thread"??

I am perfectly aware of what SSDs are good for, how much they cost, and what they can do for you and I've previously stated what applications I think benefit most from them. You're perfectly free to disagree with my opinions, naturally...

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Guest russofris
If you're trying to point out something that you think I missed, why don't you put that in a message, rather than a vague "re-read the thread"??

Cas mentioned the NV SSD's, then you corrected him telling that there, in fact, were NV SSD's. I was simply assuming that you missed the 2 posts where the pro's and con's of NV SSD's were discussed.

While everyone with a digital camera knows that NV/flash ram exists, I got the distinct impression that you thought that we had missed something. Having generic SDRAM powered by a UPS does not make the RAM NV. It makes it ummm... Power failure redundant?.... Cant seem to find the word for it. How about, "No different than a RAMdrive on a system on a UPS".

If I am in error here, I sincerely appologize.

Thank you for your time,

Frank Russo

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Guest russofris
CRAP....hold on....

Supports up to 32GB of DDR SDRAM. Try using this for your RAMDISK.

Looks like a memory riser from any ole server. Fairly commonplace in Proliants, Netserver LH's, and Netfinity's.

In the past, the problem has been that only the 8Proc servers (Proliant 8500) have supported 32GB of ram. MS operating systems have conventional support for 3.2GB of ram only, and need OS extensions added to take advantage of the rest. That still allows you to have a 28GB MS-SQL Database in RAM, and use the HDD's for logging only.

Those setups (8proc with 28GB Ramdisk and HWRAID for the .ldf's) tend to rock.

Mirroring the servers (SQL Failover or active/active clustering) tends to negate the advantage though on DB's that are heavily written to.

Thank you for your time,

Frank Russo

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