Network quality and frame rate

PrimalDesk sends the current screen as it changes. A fast speed-test result alone does not tell you whether a session will feel responsive: short stalls, changing delay and packet loss often matter more than peak bandwidth.

Read the connection, not one number

• Round-trip time (RTT) is the time for a signal to reach the host and return. Lower is better for pointer and keyboard feedback.
• Jitter is variation in that delay. A connection that alternates between 15 ms and 120 ms can feel worse than a steady 45 ms connection.
• Packet loss means some data never arrives. Brief loss can cause a skipped or late frame; sustained loss may force lower image quality or a recovery frame.
• Traffic spikes are short bursts from other devices, backups, uploads or Wi-Fi contention. They can fill a router queue even when the average transfer rate looks healthy.

These are working ranges, not service guarantees. Measure during the actual workload and at the time of day you intend to use it:

Network condition	What you may observe	Practical reading
Good	Stable RTT under about 40 ms, little jitter and no sustained loss	Usually responsive for ordinary desktop work; demanding games still depend on the host and client.
Usable	RTT around 40–100 ms, occasional short spikes or isolated loss	Documents and administration may remain comfortable; rapid motion can feel delayed.
Poor	RTT regularly above 100 ms, large swings or continuing loss	Expect visible stutter, delayed input or reduced image quality. Fix the network before raising resolution or refresh rate.

A single lost packet is not a diagnosis. Look for a pattern: does the problem coincide with Wi-Fi roaming, another upload, a VPN, a congested relay route or a busy host? Test wired networking on both ends where possible, then compare direct and relay routes.

Host FPS, local FPS and refresh rate

Host FPS describes how many new frames the Windows host captures and prepares. Local FPS describes how many frames the client actually presents. The difference can point to encoding, network delivery, decoding or presentation pressure; neither number alone identifies the cause.

A display set to 120 Hz can show at most 120 distinct updates per second. It does not guarantee a 120 FPS video stream. A game might produce only 60 FPS; an idle desktop might send very few frames; the GPU encoder, client decoder, resolution, network or power-saving policy may impose a lower rate. Increasing the display refresh setting does not create frames the host never produced.

When troubleshooting, compare the two FPS readings during motion, then check latency and discarded-frame reasons. If host FPS is already low, investigate the application and host resources first. If host FPS is healthy but local FPS falls, inspect the network and client presentation path.