When I place an SSD, would it still be the bottleneck?

Question

When placing an SSD in a new system, would the SSD still be a significant bottleneck?

If it's still a bottleneck, how fast would an SSD have to be to not be the bottleneck anymore?

Answer 1

How long is a piece of string?

The hard drive is nearly always the bottleneck for modern systems, I am not sure anyone has ever mentioned how fast a hard drive would need to be.

As for would it still be a significant bottleneck, the answer is yes, SSDs are great for reading data and tasks such as loading an Operating system can be significantly improved, but benchmarking has shown that writing is slower compared to traditional disks, so if installing or doing data intensive writing tasks, it could actually be worse.

The second part of your question is really impossible to answer as a hard drive is only the bottleneck when you are performing I/O tasks - therefore I would put in a guess figure of say 100TB/s with 0 latency - this would mean that you can write pretty much any (modern) file instantly and would mean that the SSD would not be the bottleneck (as long as the I/O controller could match it!)

Answer 2

If you think of this from a theoretical point of view, the disk subsystem (disk, controller, etc) will be a bottleneck until accessing data on disk is as fast as accessing data in main memory. Then main memory will be the bottleneck until it is as fast as accessing data in cache. You can play tricks with prefetching, scheduling, etc., to hide the problems, but there will always be situations where the problem can't be hidden.

Answer 3

Yes, SSD will still be a significant bottleneck when working with high I/O tasks, just as others have said.

As for second part of your question, the answer is that it will need to be as fast as controller on motherboard or PCI-E bus depending on the type of SSD you obtain. PCI-E SSDs are much faster, but be prepared to spend couple of thousands of $ on one. Here's a nice article to get you started.

I think that SSDs will be the main bottleneck for quite some time. Sure, people are now impressed how fast they are, but as soon as they become commonplace everybody will start moaning how slow their 1000MiB/s SSD is.