Seagate Solid State Hybrid ST500LM000 500GB 8GB/64MB Cache 2.5" 7mm SATA 6.0Gb/s Int SSHD Hard Drive $79@Newegg

Not for or against this product yet. I remember a year ago X-mas / Blk friday time the 500GB XT was "on sale @ new egg for just under <$100 ran across the screen shot not long ago, having dropped to almost half that in the interim. With less Nand but faster rpm platters - though since then the 5400rpms have increased in I/O speed don't know how close it is to the original 500GB XT's speed yet. And the 500GB XT seemed to have it's share of problems.
Since then the 750XT has been down to $100+/- on numerous occasions and was more reliable, and was a nice choice.

I'm glad to see an update but would have liked to have seen the 7200RPM drive speed return.
Hoping that the NAND size will indeed be larger in the additional models, and looking forward to a desktop version for fun.
Thanks OP for the information didn't know these were even out.

Quote from sr71 : my mistake on the link, but it does address your contention about being marginal that macMall has it isn't really an issue - if you compare it to the current XT 500GB? or for that matter the orig which everyone snapped up at $60-65 about 6 mos. ago? so it's 20% more expensive than the 1st gen and 50% faster than the 2nd gen. some folks would say that's a win it's just like when someone chimes "same price at Amazon" w/o a clue as to whether Amazon PM'ed 15 mins ago or posted days earlier.

I think you missed the point. This drive supposedly sells at a street price of $80. Even the storagereview.com claims this in their review which came out a week before this "deal". The reason to mention others is also because one source may work better than others for some for tax/shipping reasons.

I am also questioning the 50% faster for reasons mentioned. Note that this drive comes second to the 2nd gen in every benchmark measurement in the same review and looks good only in what appears to be contrived "real-life" tests as I explained. But I am keeping my mind open for further tests. Having gone through the teething problems of the XT series, I wouldn't jump so quickly on a very new drive from Seagate especially when this is likely to be the regular street price.

Quote : I'm not here to sell the drive, but the minformation being spread is amazing. you complain about MLC - well that's in the Samsung and Plextor drives, OMG what a nightmare!

With all due respect, you are the one spreading misinformation because you don't seem to understand the consequences in a hybrid that uses the NAND for a cache vs a SSD. Yes, unlike, enterprise class SSDs, most consumer class SSDs use MLC nands. They depend on the fact that the SSD is not always completely filled up and so each cell doesn't have to go through as many erase-write cycles as you can spread the usage across the entire capacity.

When used as a limited cache, almost the entire cache will be used up and every cell will be going through repeated erase-write cycles, even more so if you have a write cache. So the solid state memory in a hybrid goes through far more cycles than the memory in SSDs. This is why the Momentus XTs used SLC memory. Using the MLC memory is a cost cutting decision that doesn't bode well for the longevity of this drive relative to the Momentus XTs. Comparing this to regular SSD usage IS spreading misinformation.

Quote : It is an alternative for folks who have a notebook and don't want to shell out almost as much as they paid for a 500GB SSD, it also is a nice alternative for folks with a drive they want to update cheaply say 250GB or old 5400RPM. It could even work for someone with a Velociraptor. just stating some facts no myth or speculation

I am not disagreeing with the above at all. Just saying that until this drive has been beta tested by the early adapters, any firmware problems fixed and more tests and reviews come out to give a credible picture of its performance, the 2nd gen 750 GB Momentus XT (not the first gen 500GB) is a better choice at the moment especially when the latter can be had at around $100 on a deal for the same reasons as you have stated.

Quote from WingsOfF : With all due respect, you are the one spreading misinformation because you don't seem to understand the consequences in a hybrid that uses the NAND for a cache vs a SSD. Yes, unlike, enterprise class SSDs, most consumer class SSDs use MLC nands. They depend on the fact that the SSD is not always completely filled up and so each cell doesn't have to go through as many erase-write cycles as you can spread the usage across the entire capacity. When used as a limited cache, almost the entire cache will be used up and every cell will be going through repeated erase-write cycles, even more so if you have a write cache. So the solid state memory in a hybrid goes through far more cycles than the memory in SSDs. This is why the Momentus XTs used SLC memory. Using the MLC memory is a cost cutting decision that doesn't bode well for the longevity of this drive relative to the Momentus XTs. Comparing this to regular SSD usage IS spreading misinformation.

Yes it will be mostly filled but usually with the most often used data which would be O/S mostly so these don't get rewritten constantly - just read, unless your most used file is a pron file - of course but again not every disk write generates NAND rewrite

Given Moore's law by the end of the wty you should be able to get one with 4X the SSD cache, if it fails. And again it is cache so the data is still on spinning metal if the NAND fails.

Quote from sr71 : Yes it will be mostly filled but usually with the most often used data which would be O/S mostly so these don't get rewritten constantly - just read, unless your most used file is a pron file - of course but again not every disk write generates NAND rewrite

Not true in the "real life" scenarios in the reviews that you are basing your support on if the drive is being used for OS, media and apps as would happen in a single drive laptop this is targeted at.

Second, the most used OS files are logs and sleep/hibernate images. These days nobody completely shuts the laptop down to keep booting up, especially with the fast start requirements. This is even built into newer OSes. These keep getting written and read everytime you close your laptop lid and open it. The image varies each time and this better be in the cache with this drive. This is a problem that stresses pure SSDs as well when they get filled up and there is no clean solution for it except keeping the SSDs not filled up too much, a luxury the cache doesn't have.

Quote : Given Moore's law by the end of the wty you should be able to get one with 4X the SSD cache, if it fails. And again it is cache so the data is still on spinning metal if the NAND fails.

Unfortunately, unlike the Momentus XT, if the NAND fails or there is a cache miss, you have a very slow 5400 rpm drive. This was another good point about the earlier gen albeit at the expense of heat generation. Here is another review that points out how bad that cacheless performance can be in this drive.

CNET review [cnet.com]

Moore's law will more likely make hybrid drives extinct as high capacity SSDs come down in price squeezing these out and motherboards come with their own on-board cache and incorporated into the OS. Platters will go the same way as records in personal devices.

There's no evidence that system logs or hibernate files need to reside in cache at all since you can resume from a pure HDD or any other media. In fact as the log grows it has to be flushed to disk. In a pure SSD this causes excessive rewrites of NAND, in a hard drive scenario like this it can be to write cache in RAM, SSD or spinning metal - it doesn't matter as long as the disk version is accurate at restart, windows req'd hiberfil to be on the system drive, not all systems do and it doesn't have to be in cache of any sort, likewise you can choose to have no page file. When you suspend the image is mostly in memory which is why all bets are off when you kick the plug so the point is moot.

Quote from WingsOfF : Not true in the "real life" scenarios in the reviews that you are basing your support on if the drive is being used for OS, media and apps as would happen in a single drive laptop this is targeted at. Second, the most used OS files are logs and sleep/hibernate images. These days nobody completely shuts the laptop down to keep booting up, especially with the fast start requirements. This is even built into newer OSes. These keep getting written and read everytime you close your laptop lid and open it. The image varies each time and this better be in the cache with this drive. This is a problem that stresses pure SSDs as well when they get filled up and there is no clean solution for it except keeping the SSDs not filled up too much, a luxury the cache doesn't have. Unfortunately, unlike the Momentus XT, if the NAND fails or there is a cache miss, you have a very slow 5400 rpm drive. This was another good point about the earlier gen albeit at the expense of heat generation. Here is another review that points out how bad that cacheless performance can be in this drive. CNET review [cnet.com] Moore's law will more likely make hybrid drives extinct as high capacity SSDs come down in price squeezing these out and motherboards come with their own on-board cache and incorporated into the OS. Platters will go the same way as records in personal devices.

Quote from sr71 : There's no evidence that system logs or hibernate files need to reside in cache at all since you can resume from a pure HDD or any other media. In fact as the log grows it has to be flushed to disk. In a pure SSD this causes excessive rewrites of NAND, in a hard drive scenario like this it can be to write cache in RAM, SSD or spinning metal - it doesn't matter as long as the disk version is accurate at restart, windows req'd hiberfil to be on the system drive, not all systems do and it doesn't have to be in cache of any sort, likewise you can choose to have no page file. When you suspend the image is mostly in memory which is why all bets are off when you kick the plug so the point is moot.

Huh? If you resume hibernation from the platters, this will be one slow machine to wake up. The whole point of having the cache is to speed that up to SSD-like performance just like a boot (which is becoming a lot less frequent), one of the main reasons to use this drive. With the same logic, you might as well say the OS files for booting can be in the HDD not in the cache. Everything can be and is in the HDD. Then why get a hybrid? We are only talking about a single drive system which is the primary reason to use this drive, so what we can do with multiple drives is moot.

The problem with having the caching algorithm in the drive is that the drive has no way of knowing what is a log file, a hibernate image, a page file, etc, because the caching is at the sector level. It can try to cache sectors that are frequently accessed but not written frequently as a heuristic but that isn't sufficient to give decent perfomance.

When people don't close most-used applications but keep them started which is becoming more common for instant-on experience, most of the application code is read from paging files or memory not from the application code files, so some of the paging file sectors need to be in the cache as well for decent performance during application switching. The kind of laptops this drive targets don't come with a lot of memory so paging is common and this is precisely why these laptops with regular HDDs feel so sluggish.

All this was done in the second generation XT firmware, I don't think they have gone back on it because they put a less durable NAND. If anything, this is supposed to be even more aggressive in caching on write. It is a calculated business risk that people replace laptops faster than they start to notice performance degradation or they blame the OS getting slow.

It is a cheaper alternative to the XTs because the SSD capacities have been increasing and prices falling but there is no free lunch, however much you want to spin it for the sake of arguing.

It's clear you have no clue as to how caching works you don't need all of hiberfil or the log within cache just enough for the next block read. It would be absurd to store all 4-16GB of a hibernate file into cache as well as defeating the whole idea of caching if you filled up you cache with a single large file which gets read once and is immediately obselete

Quote from WingsOfF : Huh? If you resume hibernation from the platters, this will be one slow machine to wake up. The whole point of having the cache is to speed that up to SSD-like performance just like a boot (which is becoming a lot less frequent), one of the main reasons to use this drive. With the same logic, you might as well say the OS files for booting can be in the HDD not in the cache. Everything can be and is in the HDD. Then why get a hybrid? We are only talking about a single drive system which is the primary reason to use this drive, so what we can do with multiple drives is moot. The problem with having the caching algorithm in the drive is that the drive has no way of knowing what is a log file, a hibernate image, a page file, etc, because the caching is at the sector level. It can try to cache sectors that are frequently accessed but not written frequently as a heuristic but that isn't sufficient to give decent perfomance. When people don't close most-used applications but keep them started which is becoming more common for instant-on experience, most of the application code is read from paging files or memory not from the application code files, so some of the paging file sectors need to be in the cache as well for decent performance during application switching. The kind of laptops this drive targets don't come with a lot of memory so paging is common and this is precisely why these laptops with regular HDDs feel so sluggish. All this was done in the second generation XT firmware, I don't think they have gone back on it because they put a less durable NAND. If anything, this is supposed to be even more aggressive in caching on write. It is a calculated business risk that people replace laptops faster than they start to notice performance degradation or they blame the OS getting slow. It is a cheaper alternative to the XTs because the SSD capacities have been increasing and prices falling but there is no free lunch, however much you want to spin it for the sake of arguing.

Quote from sr71 : It's clear you have no clue as to how caching works you don't need all of hiberfil or the log within cache just enough for the next block read. It would be absurd to store all 4-16GB of a hibernate file into cache as well as defeating the whole idea of caching if you filled up you cache with a single large file which gets read once and is immediately obselete

How exactly did you get "store all of the file" from what I wrote, given the drive has no concept whatsoever of a file as I mentioned.

It is known as putting up a strawman argument. You keep assuming others are ignorant while continuing to post ignorant statements. Half knowledge is a dangerous thing.

Sorry, I have wasted enough time correcting your understanding. Bye.

i think it is quite expensive for 500GB

Quote from WingsOfF : How exactly did you get "store all of the file" from what I wrote, given the drive has no concept whatsoever of a file as I mentioned. It is known as putting up a strawman argument. You keep assuming others are ignorant while continuing to post ignorant statements. Half knowledge is a dangerous thing. Sorry, I have wasted enough time correcting your understanding. Bye.

You showed your ignorance when you stated the resume from platters argument, it is platters because the logs and hibernate info would be constantly rewritten and flushed to platters. The older gen Momentus had read caching for the drives so any notion that all resume data and logs is magically coming from SSD cache is nonsense. It's cache-assisted at startup but can reside anyway. Your last sentence is the most accurate thing you've said on this since you're clearly backpedaling

Quote : The image varies each time and this better be in the cache with this drive

Direct quote - nobody made you say it - how do you keep an image that can be 4-20GB depending an memory and page file in cache even with compression? nice try at worming out

Quote from WingsOfF : the 2nd gen 750 GB Momentus XT (not the first gen 500GB) is a better choice at the moment especially when the latter can be had at around $100 on a deal

Please tell me where? I've been looking for about a month now and it seems like the price has shot up since the drive was discontinued. Otherwise I'll be waiting for the 3rd gen 1tb drive to hit MSRP before I get one.

Quote from sr71 : You showed your ignorance when you stated the resume from platters argument, it is platters because the logs and hibernate info would be constantly rewritten and flushed to platters. The older gen Momentus had read caching for the drives so any notion that all resume data and logs is magically coming from SSD cache is nonsense. It's cache-assisted at startup but can reside anyway. Your last sentence is the most accurate thing you've said on this since you're clearly backpedaling Direct quote - nobody made you say it - how do you keep an image that can be 4-20GB depending an memory and page file in cache even with compression? nice try at worming out

Try to read the whole post before quoting out of context. You seem to have a problem with this in the entire thread. Comprehension problems? If you must criticize have the intellectual honesty to read and understand the entire post before commenting.

Which word in the following do you not understand?

Quote : The problem with having the caching algorithm in the drive is that the drive has no way of knowing what is a log file, a hibernate image, a page file, etc, because the caching is at the sector level. It can try to cache sectors that are frequently accessed but not written frequently as a heuristic but that isn't sufficient to give decent perfomance.

The drive cannot keep the whole file/image even if it wanted to because it has no idea which secors belong to which file. So your assertion of what I said is total nonsense.

As a first approximation, it can only cache sectors that are frequently read but not frequently written but like I said that isn't good enough because certain sectors, for example, sectors that are part of a paging file would benefit from fast access even if they were frequently written so that the performance is not like a slow drive. I also mentioned the benefits for applications kept running and swapped out for the same reason. So, the caching algorithms get more aggressive and cache frequently accessed sectors even if they are written frequently as long as they have cache space available. This is a good thing and beneficial except when you use media with limited lifespan. This is where the MLC vs SLC decision becomes relevant, which started this whole debate.

You made the dumb statement that MLCs are used in regular SSDs as well, implying it should be fine for caching purposes. And you try to question my understanding of caching? Unbelievable.

Feel free to continue making a fool of yourself.