The Creality Space Pi X4 is the stronger choice when you need to dry different materials at different temperatures, want an 85 C listed ceiling, or expect a four-spool dryer to handle engineering-filament recovery. The SUNLU S4 makes more sense when four-spool capacity is the main goal and one shared drying program is enough for the whole batch.
Both products solve the same broad problem, but they do not solve it in the same way. The S4 is a capacity-first shared-chamber dryer. The Space Pi X4 divides four spools across two independently controlled chambers and adds a higher listed temperature ceiling. That chamber split matters more than brand preference when PETG, TPU, nylon, and lower-temperature materials share the same bench.
Affiliate disclosure: GoodPrints3D may earn a commission from qualifying Amazon purchases. This comparison uses current exact listings, stored product records, and buyer-fit analysis; it does not claim hands-on laboratory testing. Prices, availability, package contents, and listing details can change.
Fast verdict
- Choose the Space Pi X4: mixed materials, separate chamber temperatures, or hotter drying are real requirements.
- Choose the SUNLU S4: you mostly need four spools drying together under one shared program.
- Choose neither: your actual workflow rarely has more than one or two damp spools at once.
Check the current Space Pi X4 listing or check the current SUNLU S4 listing.
SUNLU S4 vs Space Pi X4 at a glance
| Decision point | SUNLU S4 | Creality Space Pi X4 |
|---|---|---|
| Core format | Four-spool shared-chamber dryer | Four-spool dryer split across two chambers |
| Listed temperature ceiling | Up to 70 C in the stored product record | Up to 85 C on the current exact listing |
| Mixed-temperature loads | Best when all loaded spools can share one program | Independent chamber temperature control is the key advantage |
| Best fit | Capacity-first PLA, PETG, TPU, or same-material batch handling | Mixed-material benches and hotter engineering-filament recovery |
| Main overbuy risk | Four slots go unused on a one-spool workflow | Paying for chamber control and heat you do not use |
The numbers above are manufacturer listing information, not GoodPrints3D test measurements. Confirm the current manual, spool-fit limits, power requirements, and heat-safe spool guidance before ordering.
Where the Space Pi X4 pulls ahead
The Space Pi X4 has one advantage that changes the workflow rather than merely adding another feature: the current listing describes two independently controlled chambers. That lets one side run a lower-temperature material while the other side follows a hotter program. A four-spool box is much more useful when loading four spools does not force every spool into the same heat decision.
The current exact listing also describes four-spool drying, an 85 C maximum, dual 200 W PTC heaters, 360-degree airflow, active dehumidification, desiccant regeneration, and single- or dual-chamber operating modes. Those are listing claims and should be treated as such. Still, they create a clear buyer case for nylon, PA-CF, PC, or mixed-material work where a basic warm box can become the bottleneck.
That does not mean every owner needs 85 C. It means the X4 has more useful separation between everyday spool maintenance and hotter recovery work. Read the full Space Pi X4 review if that hotter, split-chamber lane describes your bench.
Where the SUNLU S4 still makes more sense
The SUNLU S4 is easier to justify when the purchase decision starts and ends with capacity. The stored product record describes a four-spool dryer with a 70 C ceiling, PTC heating, multi-fan circulation, and support for common filament diameters. Its cleanest job is keeping several active spools on one shared drying program without cycling separate one-spool boxes.
That is a real advantage for a bench running four PETG colors, a repeated TPU batch, or several same-family materials that can tolerate the same program. Independent chambers have less value when every loaded spool needs the same treatment. In that case, the simpler capacity-first layout is not a compromise; it is closer to the actual job.
The SUNLU S4 review covers that same-program buyer lane in more detail. If maximum recovery heat matters more than slot count, the PrintDry Pro 3 vs SUNLU S4 comparison is the better next read.
Check the current SUNLU S4 listing on Amazon.
The real decision is chamber control, not four-spool capacity
Both products already clear the four-spool threshold. The useful question is what happens after four spools are loaded.
- Same material, same condition, same program: the SUNLU S4 is the cleaner fit.
- Different materials or different starting conditions: the Space Pi X4 chamber split becomes meaningful.
- One wet spool and three dry spools: neither dryer needs to run as a four-spool ritual. Dry the problem spool and store the rest correctly.
- Engineering filament that needs hotter recovery: verify the material maker's drying guidance and spool heat tolerance, then favor the X4 if its current range fits.
This is why a simple slot-count comparison misses the point. Capacity tells you how many spools fit. Chamber control tells you whether those spools can receive the right treatment together.
Three realistic bench scenarios
Scenario 1: four PETG colors for one product line
The S4 is the more direct fit. All four spools belong to the same material family, the drying target can be shared, and the main problem is keeping the whole color rotation ready without serial one-spool cycles. The Space Pi X4 can do this job, but its chamber independence is not earning much value here.
Scenario 2: PETG and TPU on one side, nylon on the other
The X4 is the stronger choice. The current listing's separate chamber control lets the buyer plan around different material guidance without pretending every spool should receive the same temperature. This is the use case that turns dual chambers from a spec-sheet bonus into a workflow feature.
Scenario 3: one wet nylon spool and three rarely used backups
Do not let four empty slots make the decision. A hotter one- or two-spool dryer may solve the immediate problem with less bench commitment. The best four-spool dryer is still an overbuy when the recurring workload contains only one problem spool.
What to verify before ordering either dryer
- Measure the actual bench space. Include lid or chamber access, filament exit paths, cable clearance, ventilation space, and the route to the printer.
- List the four spools you expect to load. Write down material family, spool dimensions, target temperature, and whether each spool is being recovered or merely maintained.
- Check spool heat tolerance. A dryer temperature that suits the filament can still be unsuitable for a particular spool. Follow the filament and spool makers' current guidance.
- Separate drying from storage. Active drying removes moisture; it does not make an open shelf a controlled long-term storage system. Plan the post-cycle handoff before buying.
- Confirm the current listing and manual. Product revisions, accessories, rated power, chamber behavior, presets, and package contents can change.
This audit also exposes the most common category mistake: buying four-spool capacity to compensate for weak storage. If three dry spools keep absorbing moisture while one spool prints, a sealed storage workflow may remove more friction than a larger heater.
Which one fits PETG, TPU, nylon, and PLA?
For PETG
Either dryer can make sense. Choose the S4 for a same-material PETG rotation and the X4 when PETG shares the box with a hotter material. Do not use the dryer as an excuse to ignore sealed storage after the cycle ends.
For TPU
TPU benefits from controlled moisture handling, but a four-spool unit is worthwhile only when flexible material is a recurring part of the workload. A single damp TPU spool does not automatically justify either box.
For nylon and engineering materials
The X4 is the stronger branch because the current listing gives it the higher temperature ceiling and separate chamber control. Follow the filament manufacturer's drying guidance and confirm that the spool itself is safe at the chosen temperature.
For PLA
Four-spool active drying is often unnecessary for a PLA-only hobby bench. Start with the dryer, dry-box, or sealed-storage decision before buying capacity that will sit empty.
Who should buy the Space Pi X4?
- Owners who regularly dry different material families at the same time.
- Users who need a listed range above the S4's stored 70 C ceiling.
- Print benches where separate chambers can replace serial drying cycles.
- Buyers who have a defined use for active dehumidification and desiccant-regeneration features described by the current listing.
Who should buy the SUNLU S4?
- Owners who need four-spool capacity more than separate temperature zones.
- Same-material batch users who want one program across the loaded spools.
- Benches already centered on the stored S4 range and filament-diameter support.
- Buyers who can name four active spools that need the box now, not someday.
Who should skip both?
Skip both when one or two spools cover the real workflow. The Space Pi Dryer Plus review covers the two-spool middle lane. A sealed box may be the better spend when the material is already dry and the problem is keeping it that way.
Also skip both if the symptom has not been diagnosed. Stringing, rough walls, popping, and weak extrusion can point toward moisture, but they can also come from temperature, flow, a partial clog, or a mechanical feed problem. Use the filament drying guide to establish a controlled baseline before turning a dryer purchase into a guess.
Final recommendation
Buy the Creality Space Pi X4 if you need four-spool capacity plus independent temperature zones or hotter engineering-material recovery. Buy the SUNLU S4 if four spools on one shared program describe the real workload. Buy a smaller dryer or better storage if four-spool capacity is only a future possibility.
The X4 wins on control and listed heat range. The S4 wins on a simpler capacity-first job. The right choice is the one that removes an actual drying bottleneck without creating a larger box that mostly stores air.
Check the current Creality Space Pi X4 price and availability on Amazon.
Check the current SUNLU S4 price and availability on Amazon.
Related dryer comparisons and guides
- Chitu Systems E1 vs SUNLU S4
- PrintDry Pro 3 vs SUNLU S4
- How to dry filament without turning it into a ritual
Amazon availability note (July 29, 2026): The prior SUNLU S4 offer is unavailable, so its purchase paths now use a current official SUNLU S4 black listing with the same four-spool, 70 C, 350 W product identity.