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Flash Drives better than Hard Disks?

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March 28, 2007 2:11:21 AM

Ive always thought that Flash had only a single pro that made it worth making - its size. Now, i start hearing that Flash drives have access times As fast as RAM(!!).

Now, this dosent make any sense because i own a USB flash drive and 3 kinds of flash memory sticks. All of those are far slower than my hard drives and certainly my RAM. I mean it takes forever for games to load on my PSP.

I know that access times and transfer rate isnt the same thing, but if the access time of flash really was as fast as RAM, then there should still be a performance difference even if the transfer rate is much slower, right?

So what do u think? Should I buy a Flash Drive or a Raptor?

Thnx!
March 28, 2007 2:44:34 AM

are you referring to solid state drives?
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March 28, 2007 3:20:19 AM

I benchmarked a flash drive and it was a hell of a lot slower than one of my HD's.
March 28, 2007 3:25:25 AM

It's the coming solid state (flash) drives that will be so interesting....

64 MB/s read--45 write, is coming soon, and the progression is suggestive that in time flash will rule. (See post in Hard Drives for further stuff).

Regarding your old memory flash sticks, they are exactly what they seem -- cheap slow and quite useful for their purposes.
March 28, 2007 3:52:49 AM

Quote:
Now, this dosent make any sense because i own a USB flash drive and 3 kinds of flash memory sticks. All of those are far slower than my hard drives and certainly my RAM. I mean it takes forever for games to load on my PSP.

maybe they are slower because they run through USB...
and besides a SSD harddrive is more ment for laptops then for a PC because they are silent and very power effecient (no moving parts) and i dont really think that i can trust the wiki's report on SSD's drives. If you've got the money to burn and you want performance stick with the raptor, if you've got a laptop go for the SSD. also i dont think that there is a 3.5 SSD around.
March 28, 2007 4:01:27 AM

Quote:

Regarding your old memory flash sticks, they are exactly what they seem -- cheap slow and quite useful for their purposes.


How can one type of Flash be worse than HDD's and another as good as PC RAM??
March 28, 2007 4:54:32 AM

Quote:

Regarding your old memory flash sticks, they are exactly what they seem -- cheap slow and quite useful for their purposes.


How can one type of Flash be worse than HDD's and another as good as PC RAM??

HDD's have been around for AGES as well, so it's a mature technology.

I believe that what people are trying to say is that a SSD has far quicker access times (good for small files) and energy efficiency than a traditional HDD but if you are looking at moving about large files then you should get the raptor, as it has a quicker transfer rate.

Also, not all memory is built the same.
March 28, 2007 7:43:31 AM

Quote:

Regarding your old memory flash sticks, they are exactly what they seem -- cheap slow and quite useful for their purposes.


How can one type of Flash be worse than HDD's and another as good as PC RAM??
seriously?!? your asking THIS question?!?
for the love of god, unlike the communist manifesto all things are not created equal.
specialisation does come into play, as does quality. why do some RAM sticks cost more then others?
I do hope you actually read the responses that you get
March 29, 2007 3:35:48 AM

Quote:

Regarding your old memory flash sticks, they are exactly what they seem -- cheap slow and quite useful for their purposes.


How can one type of Flash be worse than HDD's and another as good as PC RAM??
seriously?!? your asking THIS question?!?
for the love of god, unlike the communist manifesto all things are not created equal.
specialisation does come into play, as does quality. why do some RAM sticks cost more then others?
I do hope you actually read the responses that you get

Why wouldnt I?

Just because some things "arent created equal" does not explain why my USB flash drive is about 10 times slower than my 7,200 RPM HDD, and this SSD flash drive is about 100 faster than my 10,000 RPM HDD.

I think what explain the difference in performance is that the USB interface does not let the flash use it's actuall access time. The USB drive is very fast but the USB interface is very slow. So all in all, the USB drive becomes even slower than an HDD because now, not only does it not have good access times, but it maintains it's slow transfer rate.

So then the S.ATA interface WILL actually allow the SSD to be as fast, because its not going to be bottlenecking it's access time (as much), much like the I-RAM. Of course the DIMM slots on the motherboard are much faster than S.ATA in access times, so RAM will always be fastest when its on the motherboard.

Also SSD's are far too expensive for now, and the same goes for the I-RAM.. Raptor is it!
March 29, 2007 12:29:17 PM

whoa! there is a drive 100 times faster than a raptor??!?

check those numbers and units please, but if you're right, I wanna know!!
March 29, 2007 1:17:41 PM

Hi.

I believe you are confusing the I RAM and such RAM disks with the SSD Hard disks.
The SSD hard disks are actually SLOWER for large files compared to mechanical harddisks. They just kick ass when it comes to large number of small files due to the almost zero access times.
IRAM on the otehr hand is actually RAM modules connected through the IDE or SATA interface.
March 30, 2007 7:32:39 PM

I'm a writer so I figured it was cheaper to buy a flash drive instead of backing up my files on CD all of the time. I stopped using the floppy because I would notice a lot of errors in saved files through Microsoft Word. A few months ago, I got a 160GB hard drive on sale for about $44 so I figured that a hard drive was cheaper than buying flash drives all of the time. The good thing about flash drives is that I can take it to work and have access to all of my important files and it fits in the inner pocket of my jeans. I took my first flash drive to the Franklin Institute in Philadelphia and my nephew told me to touch a lightning display that had ten times the amount of electricity than which runs through your house. My first flash drive started acting up after that but luckily I saved the data right before it died. I'm waiting for prices to become reasonable before I buy another flash drive because I know that prices will be lower in two years and then maybe an 8 GB or larger MP3 player will be reasonable. I also suggest that people shop online and avoid the big stores because you are paying for the big name.
April 1, 2007 8:18:53 PM

Flash drive have access times as fast as RAM.

They do NOT have sustained transfer rates even as good as HDDs let alone RAM.

There we go, mystery solved. Whereas a HDD takes time to move the read head to a different area of the disk, a flash drive doesnt, but flash drives cannot read as fast as HDDs.
April 2, 2007 5:00:12 AM

Quote:
Flash drive have access times as fast as RAM.


Not even close. Quoted flash drive access to data times are around 0.1 msec (100 microseconds). Most of this overhead is in the transport protcol (USB or IDE/SATA for flash-based hard drives).

Modern RAM has access times of around 5 clock cycles at 533MHz (DDR2-533), which works out to around 2 nanoseconds. This is about 500,000x as fast as access to the flash devices.

Quote:
They do NOT have sustained transfer rates even as good as HDDs let alone RAM.


True for the most part, although many of the recent flash devices are approaching hard drive speed. The Samsung 1.8" SSD device just released has read times of 64MB/sec, which only modern SATA drives can best.
April 2, 2007 5:14:31 AM

Quote:

True for the most part, although many of the recent flash devices are approaching hard drive speed. The Samsung 1.8" SSD device just released has read times of 64MB/sec, which only modern SATA drives can best.


They're also hideously expensive and don't have the capacity of HDD's. Give it 5-10 years though.
April 2, 2007 5:21:04 AM

There is a 32 and a 64GB model for around $300 to $500, which when used as a boot drive/swap drive, substantially speeds up boot times and program load times. For those needing the best in RAID0 performance along with backup strategies, it is becoming an interesting and affordable option.
April 2, 2007 10:27:33 AM

Quote:
Flash drive have access times as fast as RAM.


Not even close. Quoted flash drive access to data times are around 0.1 msec (100 microseconds). Most of this overhead is in the transport protcol (USB or IDE/SATA for flash-based hard drives).

Modern RAM has access times of around 5 clock cycles at 533MHz (DDR2-533), which works out to around 2 nanoseconds. This is about 500,000x as fast as access to the flash devices.



So ur saying that 0.1ms is 500,000 times slower than 2ms?

Interesting..
April 2, 2007 11:46:15 AM

Quote:
Flash drive have access times as fast as RAM.


Not even close. Quoted flash drive access to data times are around 0.1 msec (100 microseconds). Most of this overhead is in the transport protcol (USB or IDE/SATA for flash-based hard drives).

Modern RAM has access times of around 5 clock cycles at 533MHz (DDR2-533), which works out to around 2 nanoseconds. This is about 500,000x as fast as access to the flash devices.



So ur saying that 0.1ms is 500,000 times slower than 2ms?

Interesting..

No, he is saying 100 microseconds is slower than 2 nanoseconds. And he is correct. 100 microseconds = 100,000 nanoseconds.
April 2, 2007 12:42:35 PM

Quote:
Flash drive have access times as fast as RAM.


Not even close. Quoted flash drive access to data times are around 0.1 msec (100 microseconds). Most of this overhead is in the transport protcol (USB or IDE/SATA for flash-based hard drives).

Modern RAM has access times of around 5 clock cycles at 533MHz (DDR2-533), which works out to around 2 nanoseconds. This is about 500,000x as fast as access to the flash devices.



So ur saying that 0.1ms is 500,000 times slower than 2ms?

Interesting..

No, he is saying 100 microseconds is slower than 2 nanoseconds. And he is correct. 100 microseconds = 100,000 nanoseconds.

It is not correct as the math is off:

1 msec = 1000 ns

so

0.1 msec = 100 ns

thus if the RAM runs at 2 ns, that is 50x quicker, not 500,000 times as fast.

EDIT: I read his post wrong. What a strange morning for me. :)  His math is dead-on.. It IS 500,000 times as fast:

100 msec = 100,000 ns

Thus, 2ns is 500,000 as fast.
April 3, 2007 9:52:09 AM

Either way, flash and ram both have "perceptibly instant" access times, while hard disks do not. Perhaps that is what I should have said :p 

However, small expensive 32GB flash drives have a much lower sustained transfer than hard disks.

Lets compare the 60MB/s you might get out of one of these disks to the first 32GB of a 150GB Raptor. Yes the speed drops off slightly to the end of the disk, but this is space you wouldn't even have on the flash disk.

The Raptor will be pushing close to 90MB/s here, with an average of maybe 80-85MB/s. Thats nearly 50% faster than the flsh disk.

Yes you can do RAID0 across those flash disks, but that makes for an insane cost. For the cost of 2*32GB flash drives in RAID0 you can have 4-6 150GB Raptors in RAID0, which will give a much much higher sustained transfer.

Flash also has a limited number of Read/Write cycles.

I can't see flash taking over from hard disks until the capacities, and sustained transfer rates, are at least as good, and the read/write issue is gone. Oh, and the cost is at most 30% of what it is now.
April 4, 2007 4:30:41 AM

Quote:

I can't see flash taking over from hard disks until the capacities, and sustained transfer rates, are at least as good, and the read/write issue is gone. Oh, and the cost is at most 30% of what it is now.


A company called Adtron (no, I never heard of them until today either) has created a 160Gb SSD, so capacity (in notebook land at least) is no longer an issue...until Foxconn releases its 600Gb monster. 8)

Price and transfer rates though...
April 5, 2007 10:30:39 PM

I imagine in a year or two they will be coming commonplace, and prices will be affordable.
!