>>>I have another questions about replacing the hard drive with SSD. I am pretty much convinced that SSD is the way to go.
>>>
>>>Dell quoted Western Digital SSD and I found that Samsung, supposedly, the fastest and a "Pro" grade SSD drive.
>>>Aside from the prices (where Samsung is the most expensive, about $450), I want to be sure that the dimensions of the SSD will fit into the existing laptop.
>>>
>>>I found that what I have now in my laptop is HGST Travelstar 2.5-Inch 500GB that has the following dimensions:
>>>3.94 x 2.76 x 0.28 in
>>>
>>>The SSD drives (both WD and Samsung) have the dimensions:
>>>2.75 x 3.94 x 0.27 in
>>>
>>>Do you know what is the second number (2.76 vs 3.94)? The SSD has it about 1" larger which concerns me.
>>>
>>>TIA for any suggestions/input on this dimension.
>>
>>There are a few considerations when replacing a mechanical HD with an SSD:
>>
>>1. 2.5" drives come in 2 thicknesses, 7mm and 9.5mm. The one thing you have to avoid is trying to put a 9.5mm drive in a slot that's only 7mm thick. Chances are you'll be OK: most mechanical drives are 9.5mm as they need all the thickness they can get, so your slot is likely that size. Many current SSDs using 3D NAND are 7mm, but most include a 2.5mm spacer so they will fit properly in a 9.5mm slot.
>>
>>2. Check the speed of your computer's SATA interface. Probably it is either SATA II (3Gbps) or SATA III (6Gbps). Serial protocols such as SATA and USB employ error correction, and encode 8 bits (1 byte) in 10 bits so the theoretical maximum throughput of the two interface types is 300M bytes/sec for SATA II and 600M bytes/sec for SATA III.
>>
>>Current SSDs in the 500GB - 1TB class have read and write speeds both in excess of 500M bytes/sec. If your interface is only SATA II then there is no use spending extra money getting the absolute fastest SSD, as it will be limited by the interface to only 300M bytes/sec. If the interface is SATA III then you can think about getting the highest performing drives, but be aware that anything over 600M bytes/sec will not be utilized on a SATA III interface.
>>
>>3. As others have mentioned, many SSDs come with cloning software (Acronis True Image is a popular choice). Acronis for one has a couple of features that may be useful:
>>
>>- If you have a large mechanical drive e.g. 1TB, but you're only using, say, 200GB of it then Acronis will let you clone to a 512GB SSD. It might let you clone to a 256GB SSD but that wouldn't give you a lot of expansion room.
>>
>>- If you have multiple partitions its automatic mode can proportionally resize partitions to fit what's actually being used. There is also a manual mode for more complicated scenarios.
>>
>>- Note that any hardware change may upset some software licensing schemes. I upgraded one workstation for an accountant, and none of her various QuickBooks installations would work afterwards, giving error messages about licensing. She had to call Intuit to get it sorted out
>>
>>4. Some new laptops (and desktop motherboards) come with so-called M.2 slots. M.2 devices can be either SATA or PCIe based. M.2 PCIe is much faster than SATA II or SATA III. In laptops an M.2 slot is sometimes used by a wireless network adapter so it's not available for other use. But if your laptop has an available M.2 PCIe slot which will support an SSD then an M.2 SSD would be an interesting option.
>>
>>5. In the past I've found Dell's prices for hardware upgrades to be ridiculously high. If you're considering getting parts through them make sure their prices are competitive. Also be aware that the warranties on parts they resell may be much shorter than the manufacturer's warranties, which when coupled with higher prices is a real downer
>>
>>The performance gains with SSD are large. A typical mechanical drive might peak between 70-100M bytes/sec in the best-case scenario, often much lower. As mentioned above a typical SSD will reach 300M bytes/sec on SATA II and up to 500M bytes/sec on SATA III.
>>
>>There's an even greater gain in multitasking performance. If you're running multiple programs at once (and/or Windows services such as SQL Server) which are all accessing the HD, then an SSD's vastly greater I/Os per second (IOPS) can keep them all happy and humming along. Mechanical hard drives get really sluggish at large queue depths, which is one area where SSDs really shine. A mechanical hard drive might support 100 - 200 IOPS, current SSDs typically offer tens of thousands of IOPS, with some models exceeding 100,000 IOPS.
>>
>>NAND-based SSDs do "wear out" over time - NAND cells can only be written to a limited number of times. However, SSDs employ some techniques to mitigate this such as overprovisioning, wear leveling and TRIM so an SSD in typical workstation use will last much longer than the workstation itself. Speaking of TRIM, in Windows you may need to ensure it's enabled for your SSD. You can Google [windows 7 ssd trim], for example.
>
>First, thank you very much for your detailed input.
>
>>> Check the speed of your computer's SATA interface. Probably it is either SATA II (3Gbps) or SATA III (6Gbps)
>Where do I see it on my existing computer? I see from Amazon page that the 1 TB SSD has SATA III 6Gb/s. But I don't know what my existing 500 GB drive is.

You can't tell the speed of the interface from the drive that's currently installed, you have to look at the specifications of the computer itself. If it's a Dell you can enter your express service tag at support.dell.com , which should offer you specs, manuals or your original as-delivered computer configuration.

SATA II and SATA III are interoperable, they will negotiate the best speed both support at boot. For example:

SATA III computer/interface, SATA II hard drive - speed will be SATA II 3Gbps
SATA II computer/interface, SATA III drive (HD or SSD) - speed will be SATA II 3Gbps
SATA III computer/interface, SATA III drive (HD or SSD) - speed will be SATA III 6Gbps

Note that many purely mechanical hard drives now offer SATA III interfaces. IMO it's putting lipstick on a pig, as no single HD can saturate even SATA II. There is a tiny gain when transferring data to/from the HD's small RAM cache but for any sort of sustained operations there's no gain at all.