Hi!
I have an SSD as OS drive. I plan on installing Dolphin on my HDD (not my OS drive).
SSD's have limited write cycles. I am a bit concerned if Dolphin will be writing data to the SSD.
If I install and use Dolphin on the HDD, will it write anything to the SSD?
Thanks in advance, and have a great day!

Unless you tell it to write data to the SSD, or it deposits data to the my documents folder (which if you are worried about the limited write cycles you shouldn't even have on the SSD) when you have it on the SSD, it will have no need to write to the SSD.
If you own an Intel SSD , you'll be fine (not sure about other brand though)
I daily write many data on the SSD which I bought it 1.5 years ago
Yeah , my PC run 24/7 , no problem so far
Edit : Intel SSD can write 20GB/day for 5 years (google)
dolphin only writes to the folder, and you should not have bought an ssd for not using it
you paid for it, the use the shit out of it
That's the problem with the non-volatile (keep their data after being disconnected from power) SSDs. If you use them it makes their life shorter as they have limited write cycles. It isn't really a problem you'll notice unless you keep the SSD for decades or use it for virtual memory, but people are scared to break their £75 30GB drive. After all you could get a 32 GB SD card for less, although it would be ridiculously slow in comparison. Also you get what you pay for: a cheap drive, even if well managed could die in two years, and as even a cheap one is ridiculously priced it is too much money to waste, so people are super careful.
Using anything makes its life shorter. If I use bacon, it'll also be gone afterwards. Also, HDDs break too. So, what the hell, just use your hard drive and if it breaks buy a new one. What's the problem? :]
When a hard drive breaks it is because it is broken, but when an SSD breaks it is because you've been stupid with it.
Anyhow, I'd like to clarify that I don't own an SSD and wouldn't get enough benefit to justify the cost.
Yeah, you're right, there's a difference; HDDs tend to break after $n power-on hours, while SSDs tend to break after $m write cycles.
I bought a SSD disk a few months ago, and I didn't have any problems with it. SMART reports no bad blocks after 860 power on hours. Plus, it's noticeably faster than a normal HDD. Also relevant for a notebook: it won't break for sure if you drop it.

I sure expect it to break after ~3 years, but I can just replace it then. It's not *that* expensive.
I'd still go for a Terabyte of HDD over 40GB of SSD any day.
I'd also take a 2 Petabyte floppy disk over a 16 Byte USB stick. [/irony]
No seriously, 40GB is a bit small, but you can get 128GB for not that much money, which is enough for most of the stuff you'll need everyday (for me at least); I got everything else on my external drive.