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Seagate's New SSHD Hybrids Have Dual-Mode Flash Caches
crookedvulture writes "Seagate's has revealed its next-generation hybrid drives, and for the first time, there's a 3.5" desktop model in the mix. The new family of so-called SSHDs includes standard and slim notebook variants with 500GB and 1TB capacities, plus 1TB and 2TB desktop versions. All of them combine mechanical platters with 8GB of NAND in a dual-mode SLC/MLC configuration. The SLC component is largely reserved to cache host writes, while the MLC portion is filled with frequently accessed data to speed read performance. Despite MLC NAND's lower write endurance, Seagate claims the SSHDs have more than enough headroom to last at least five years with typical client workloads. More impressively, the mobile SSHDs are supposed to be faster than the old Momentus XT hybrid even though they have slower 5,400-RPM spindle speeds. The mobile models are slated to start selling shortly at $79 for 500GB and $99 for 1TB, while the 1TB and 2TB desktop flavors are due in late April for $99 and $149, respectively. Unlike other NAND caching solutions, Seagate's tech requires no software or drivers, making it compatible with any OS."
1. Cheaper
2. Less headaches while configuring.
Bonus: All your data will be cached, not only what's on the SSD (OS + core programs). That includes the games you have installed on the HDD. (When you have a 120 GB SSD +1 TB HDD setup you typically do not install games on the SSD.)
For a mere 8GB acting as cache in the drive, I'd rather spend $30 on RAM and let the OS use it for buffering/caching data (which Linux at least will do pretty intelligently for me even without changing /proc/sys/kernel/whatever).
I love my SSD but that's way more than 8GB. As an extra bonus, the RAM can be allocated as necessary, is faster, and there are no write/erase issues with it.
Now, come up with say 2TB on platters and 128GB flash and we're talking a different proposition.
8GB might be sufficient for those who care about how quickly they boot up (assuming the bulk of the kernel etc ends up in the flash cache and stays there until shutdown) but I only reboot about once a month at most.
Its unlikely that many of your games will end up on the cache seeing as its only 8 GB.
You don't know how this works. The firmware recognizes individual HD sectors that are frequently read, and transparently copies them to the SSD.
"When I first heard Daydream Nation it quite frankly scared the living shit out of me." -- Matthew Stearns
Spoken like someone who hasn't actually used a latest gen SSD yet. I used to be on your bandwagon, thinking my striped raid was good enough.
There is just no getting around the fact that essentially zero seek times and 400MB+ reads and writes are just so much better than platters can manage.
I will never build another computer without at least a small SSD for the OS and related software.
If sharing a song makes you a pirate, what do I have to share to be a ninja?
Flash makes little difference to read performance, but can make a huge different to write speeds. RAM, being non-volatile, means that if an application calls fsync, you block until all of the data has been flushed to the disk. With a flash write cache, you can buffer a load of writes and return almost immediately (writes into flash can easily go at 100+MB/s) and then write them out to disk when it is idle or less loaded.
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I have the first gen XT and I can say is that these things are everything they're cracked up to be. If you're not buying an SSD then you should be getting one of these. Generally if you strip away the SSD portion you're still left with one of the best mechanical drives on the market, but the SSD portion really and truly does make a solid and positive difference in everyday computing life.
"Once your RAM file cache is more than the files you load, file access is essential zero seek and 2GB+ reads and writes. Don't forget here we're talking about RAM. The disk is NEVER touched once its cached, there's no possibility for a disk that isn't being accessed to speed up a read from the RAM cache, and no benefit from speeding up a deferred write that's done in the background."
You don't know how writes in a filesystem work. It isn't just the data that gets written and not every write can be deferred.
If your "disk light never blinks" you aren't using your computer.
Actually it's not. You can create a hybrid volume from any two drives easily via terminal. You can find the instructions to do so with a few seconds of Googling.
The restriction on dual boot is not related to the hybrid, but rather due to the EFI and limitations in Windows.
Windows can’t boot from drives larger than 2TB in the absence of an EFI or UEFI BIOS.
Given that the most read sectors probably contain parts of your OS and pagefile, and considering the size of a modern OS
If you're reading/writing to the pagefile more than just a very little, you're running the performance equivalent of a 200MHz Pentium 686. Not kidding. People seem to think swap is a thing that happens a lot; it isn't. You know how you have 16GB of RAM and you're like 1.2GB into swap somehow? That's 1.2GB of program initialization crap and other cruft that NEVER GETS TOUCHED and was paged out.
You know how you're only using 6GB of RAM, but somehow you have 1.2GB in swap? 10GB of that shit is pagecache so your OS doesn't have to re-read operating system files (among other shit) constantly. That stuff gets read at boot time.
Computers don't work by churning the hard disk a lot.
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>How about those typical client workloads where almost every day is needed to manage 16-30 gigabytes of new data,
That's not a typical client workload. Go buy a large SSD or some type of SSD accelerator. Quit bitching this product doesn't fill your needs when it's better then the previous product at the same price point. If you want fast speeds with large data sets, open your wallet not your mouth.
>Granted they're faster than most peoples 5400rpm drive running in their laptops,
Not just faster, way faster. I've upgraded a number of clients computers from the crap HP comes with by default to XTs with the 8GB cache. Unless they have a very large working set of data they commonly use, the user will not notice a significant difference between the SSHD and an SSD.
If you tell most consumers do you want a 500GB SSD for around $500 or a 500GB SSHD for $79 where the $79 drive makes most, but not all things faster, most people will go with the second option, and most people will have made the right choice going with the second option.