Solar imaging - computer write speed/FPS values?

[Radon86]

Hi, I have tried to look and search but have not yet been able to work out :
A reasonable imaging computer (acquiring data from camera) would have ideal values of:

1) write speed in Mb/second
2) frames per second for about frames with 1280 x 960 pixel image size

In Sharpcap, there is a Test Write Speed function. I don’t know if Firecapture or other capture software have this.
For a) Thinkpad W510 laptop with i7 quadcore 1.73 GHz, 16 GB ram, 500 Gb SATA2 7200 rpm hard drive, Windows 10 apro 64 bit OS, the results are : 215 Mb/s, 205 FPS.

b) Thinkpad T400 laptop, Core duo 3.4 GHz, 8 Gb ram, 240 go SATA2 SSD, windows 10 pro, 64 bit OS, the results are : write 191Mb/s, 163 FPS.

I assume this is with USB3.0 ports.
For a slower Atom 1.33 GHz, 2Gb ram, and 32GB eMMC and Windows 10 home 32 bit, it’s about 44 Mb/s and 38 FPS.

What would be your values for write speed and FPS ?

I am asking because my laptop is only usb2 and more towards the slow Atom laptop, what do I need to upgrade to without spending 2000 pounds on a better laptop?

Many thanks,
Magnus.

[Rusted]

Hi Magnus,

Thank you for bringing this SharpCap facility to my/our attention.
I am seriously unqualified to be answering your question but can relate my recent experience.
Being a recent convert to Solar H-alpha imaging I had to equip myself from scratch based on my online research.

High speed cameras like ZWO ASI now use USB3.
Better/modern laptops typically use SSDs instead of disk hard drives.
Lots of RAM is also mentioned as beneficial for improved speed.

My ZWO ASI74 typically shows 319fps during solar disk capture. Slower on proms and disk limb segments.

I have an i7, 8-core, 15.6" ASUS laptop with internal [and external USB3 SSDs] and 16GB of Ram.
It cost about £1.2k equivalent a couple of years ago. My very fist laptop!

The onboard 256GB SSD fills up very rapidly in a typical, solar imaging session.
So I added a 500GB SSD and then a 1TB SSD later just to cope.
I sometimes capture 1k, 2k mostly and 3k videos rather less often.

I don't use the laptop's onboard screen but close the lid and use an external 25" LCD screen on HDMI.
Not sure if that helps the computer speed but at least I can see what I am capturing.

I might gain more speed if I didn't have half a dozen programmes open all the time. I often process while I capture.

When I am backing up my video SSDs to my 4TB Seagate disk drive via USB3 the speed is agonizingly slow!
Transferring from internal SSD to T5 external SSD I typically see 300Mbps. Never the "up to 500" they claim.

If I had any sunshine I'd be checking this SharpCap facility ASAP.

[MalVeauX]

Heya,

Ideally you want USB3 cameras and a USB3 capable (or better) bus on your imaging laptop. I have a dirt cheap ($150) used (from ebay) Toshiba satellite laptop, nothing special, just an i3 or i5 CPU, but I got it specifically for the USB3 and I installed a 1TB SSD (Samsung EVO) into it. I have a powered USB3 hub that I plug into the laptop and everything else plugs into the powered hub. I don't get "max" FPS that are listed as potentials, but it keeps me in the 80 FPS range at full pixel array typically which is good enough for me (IMX174, ASI290, IMX224, etc).

If you want speed, you need a new computer. They're not expensive. You don't need a desktop replacement class laptop. Just something that turns on and has USB3 and the ability to put an SSD in it as a harddrive and you're set.

Very best,

[rsfoto]

Hi Magnus,

Sharpcap uses RAM as buffer and so if the write speed of the disc is not up to the task it does not matter.

I can test later on what my desptop in the Observatory report.

I have an ASI 290MM cool and that is 1936 x 1096 pixels and I can stream in 8 bit about 160 frames and in 16 bit the half e.g. 82 or something.

Rainer

[Radon86]

Thanks guys for your help, Rainer, Marty, and Rusted.
It’s like I should be getting at least a i5 or i7 quad core or higher processor, 1TB SSD maybe PCie nvme 1000 GB SSD, 16 Gb ram, and usb3 preferably powered usb3 hub as Marty uses!

I will test Marty’s setup as that does not seem that expensive, thanks Marty, Rusted and Rainer,


Magnus.

[Radon86]

Thanks Rusted, that’s an interesting idea to use a large 25 inch LCD screen instead of the tiny laptop screen!

Magnus

[Rusted]

Thanks Rusted, that’s an interesting idea to use a large 25 inch LCD screen instead of the tiny laptop screen!

Magnus

Hi Magnus,

25" may be on the large side. A 23" or 24" would easily have done for me. It depends on your comfortable viewing distance from the screen in imaging practice and whether you use reading glasses.

My maximum viewing distance is limited by my chair being pushed back against the observatory wall. With the screen mounted on the timber pier at a comfortable height in front of me. My 24" indoor PC screen is at a slightly greater distance and suits my weak, reading glasses slightly better.

Another complication is regularly adjusting screen resolution [in Windows] to match the difference between the laptop and monitor. Some of our favourite astro and image processing apps do, or did not, automatically adjust their text and icon sizes to match these changes.

This drove me crackers at first! Because the magic "visibility" button was well hidden in microscopic text in drop down menus I couldn't even see with a magnifying glass! So you have to adjust the "magnification" factor, in Windows, to suit your own needs. Or find the necessary adjustment button in the app on normal resolution screen.

This all seems like far too much information but a good screen is not a trivial expense for most of us. Best to check out screen sizes and comfortable viewing distances for yourself before investing. I bought mine online based on my indoor screen size but didn't weigh viewing distance accurately enough. Though I am not remotely disappointed in the screen it was all a bit "Home Theater" at first!

[MalVeauX]

Magnus,

This is not my ad, just an example, but I just look for used laptops on ebay or anywhere really that you can locally, not sure where you are. Businesses sell their equipment often to rotate in new stuff and they sell refurbs that way. You can look for an i3 or i5 based system, any size, with USB3, 4Gb or more RAM, any size SSD (you can replace this yourself easy and cheaper likely). And then just get a powered USB3 hub.

Ex of something I'd look for, inexpensively:

https://www.ebay.com/itm/Windows-7-or-1 ... keKmtvljYQ

Then I'd just put a 1TB SSD in it (a fast one, samsun evo series). Powered USB3 hub. It already has 8Gb RAM, so its pretty set, but you could likely upgrade this as needed, RAM is cheap these days.

Very best,

[Radon86]

I agree Marty with you. I have been reading about the various options for SSD and RAM and CPU configurations, and I will try your method first.

Now, it’s time to look for a bargain laptop.

Thanks for the warning about LCD screen sizes, there are problems with setup etc.

Magnus

[BGazing]

Bumping this.
When capturing 10Gb files for the whole disc (30 secs), capture is quick, but later write (from RAM?) to extenal SSD is fairly slow, like 6-7FPS.
Any cure for that?

[rsfoto]

What would be your values for write speed and FPS ?

Hi,

I do not know my write speed but I do know that I have between 14-16 fps for my H-alpha images

[DeepSolar64]

Me? I certainly prefer a computer with USB3 or greater with a Solid State Drive. 16gb of RAM or better. My Windows computers fail on the RAM and SSD but do have USB3. My new iMac passes easily but unfortunately MacOS is more limited on what it can run. On what programs are available for it.

James