For your computer… Here's a quick assessment here…
* CPU -- Reasonable, no upgrade needed -- ~3.4 Ghz Quad-core processor is acceptable, even though it doesn't have any HyperThreading features. Ryzen 3 1300X would be an equivalent processor on the AMD side, so I would have to look at a Ryzen 5 1500X or higher to improve your CPU performance.
* Graphics -- INSUFFICIENT INFORMATION / UPGRADE REQUIRED -- The AMD R7 appears to be INTEGRATED GRAPHICS… Like Intel HD graphics, which is HORRIBLE FOR GAME PERFORMANCE. Your system is likely compensating by utilizing the CPU for graphics processing, which will drop your framerate when you try to broadcast on Twitch (since OBS is CPU-intensive, it doesn't leave a lot for graphics processing).
You will want to get a DEDICATED Graphics card… A Nvidia GTX 1050 or AMD RX 560 (which are equal in terms of performance) to improve performance on the graphics side. HOWEVER, if you have an AMD R7 260x or R7 360 (which are dedicated cards in the same vein), your performance would be better than integrated graphic, but I would still recommend the upgrade. As the R7 360 is closer to the RX 550 & the R7 260x falls between RX 550 & RX 560.
RAM -- Acceptable, Upgrade Recommended -- 8 GB's is minimum recommendation for gaming & broadcasting… Which is reasonable. Upgrading to 16 GB's can help with higher-end games, but isn't a critical deal.
One thing that was NOT MENTIONED AT ALL is your internet connection, SPECIFICALLY YOUR UPLOAD SPEEDS! You could have a high-end, "no expense spared" system & still have a garbage stream if your internet connection skimps on upload speeds. This is fairly common with residential grade connections (as ISP's typically assume you'll be downloading way more content than uploading, so they cut back on the upload speeds as a cost-cutting deal).
For streaming on Twitch at 720p @ 30 fps with reasonable quality, you'll need to have 1.5 Mbps (1500 Kbps) upload speeds AT A BARE MINIMUM. For 720p @ 60 fps (or 1080p @ 30 fps), you'll need to have around 5 Mbps (5000 Kbps) upload speeds. 1080p @ 60 fps, you'll want around 7.5 Mbps (7500 Kbps) or higher.
Please be aware that these figures INCLUDE a 20% Overhead BUFFER… As you'll never be able to fully utilize your entire your upstream because of online games, monitoring chat, other connected devices using stuff, ect. At most you'll be able to utilize around 75-80% of your upload bandwidth at one time before you start suffering major framerate droppage (which OBS does track dropped frames)… So you'll want to set your broadcast (upload) bandwidth to…
* 720p @ 30 fps -- ~1200 Kbps (1000 - 1200 Kbps range)
* 720p @ 60 fps / 1080p @ 30 fps -- ~3000 Kbps (2000 - 4000 Kbps range)
* 1080p @ 60 fps -- ~4500 Kbps (3000 - 6000 Kbps range)
Please be aware that Twitch tends to place a bandwidth cap around 6 Mbps (6000 Kbps) on streams since 4K isn't available at this time, so anything over 6 Mbps is wasteful. Additionally, you'll want to set your broadcast bandwidth to a level that most of your viewers will be able to consistently stream with minimal issues as Twitch since it's unlikely their servers will offer you transcoding services (which processes your broadcast into various "quality" levels, running at different bitrates) until you get into the Partnership program OR get a VERY POPULAR broadcast (As Affiliates get priority offerings for transcoding, but is generally provided based on realtime viewer numbers). If your bitrate is too high, viewers may experienced dropped frames or worse, get stuff in "rebuffer hell" (where the stream rebuffers every 5-10 seconds). If your bitrate is too low, everybody experiences "Block Land" (heavily pixelated & poor quality)… So it's a challenge to find that "Goldilocks zone".
If your internet connection has an upload bandwidth speeds UNDER 1.5 Mbps (1500 Kbps), you'll want to talk your ISP about it & adjust your service plan accordingly.
Hope this sheds some light on the subject to improve your broadcasting experience.
