Specification-first purchase decision
Creality Space Pi X4 vs SUNLU S4: 85°C vs 70°C
Creality Space Pi X4 vs SUNLU S4 is not a spool-count decision: both hold four standard spools. Creality documents two independently controlled two-spool chambers reaching 85°C. SUNLU documents one four-spool system reaching 70°C with automatic humidity control and eight feed holes.
The SpacePi X4 is the stronger paper fit for two material types that need different temperatures or for formulations requiring more than 70°C. The SUNLU S4 covers four-spool, multi-printer workflows whose exact filament instructions stay within its 70°C ceiling. Neither specification proves chamber uniformity.
Which one fits your actual load?
Buy the second temperature zone only if you will use it.
Both hold four standard spools. The deciding question is whether those spools can share one safe drying cycle—not how many feed holes are on the box. This comparison is for the standard SUNLU S4, not the S4 Pro.
On a small screen, scroll the table sideways to compare all columns.
| Your requirement | Better specification fit | What to check before paying |
|---|---|---|
| Four spools, one cycle at or below 70°C | Either can fit. The S4's shared chamber is sufficient on paper; X4's second zone is not essential for this job. | Compare the delivered price, usable spool dimensions, voltage, warranty and return route. Do not assume either is cheaper in your region. |
| Two pairs of spools needing different temperatures | SpacePi X4: two independently controlled two-spool chambers. | Each pair must still share a safe setting. Four bays do not mean four independently controlled temperatures. |
| An exact filament cycle above 70°C and no higher than 85°C | SpacePi X4 clears the temperature ceiling check. Standard S4 does not. | A rated ceiling is only a screening result. Confirm the required drying method, time, spool heat limit and actual loaded-chamber conditions. |
| A prescribed cycle above 85°C | Neither dryer clears the temperature requirement. | Look for a suitable higher-temperature system; do not assume that extra time compensates for insufficient heat. |
| An S4 Pro listing, rather than an S4 | Use the separate S4 Pro comparison: it also has an 85°C ceiling and two independent zones. | Check the exact model on the listing and box before applying the S4's 70°C limitation. |
Humidity control is not proof that the spool is dry. SUNLU documents a selectable 30–50% RH restart threshold and a 25% stop point. Creality documents active dehumidification, desiccant and a one-way valve. These are control features, not a measurement of moisture inside the filament.
Already own an S4? Keeping it is reasonable if your real loads share a cycle within 70°C. A move to X4 solves a specific higher-temperature or simultaneous two-temperature need; the four-spool label alone is not an upgrade.
Direct answers
The questions that change this purchase.
Which gets hotter: Creality Space Pi X4 or SUNLU S4?
Creality documents an 85°C maximum for the Space Pi X4, while SUNLU documents 70°C for the S4. A maximum rating still does not prove uniform spool temperature.
Do both dryers hold four spools?
Yes. The X4 divides four spools across two independently controlled two-spool chambers. The S4 uses one shared four-spool chamber with eight feed holes.
Can the SUNLU S4 replace the Space Pi X4 for every filament?
No. Reject the S4 when the exact filament instruction exceeds 70°C. Reject either dryer when the required cycle exceeds that product's documented ceiling.
Is the SUNLU S4 the same dryer as the S4 Pro?
No. The S4 in this comparison is a shared four-spool chamber rated to 70°C. SUNLU's newer S4 Pro documents two independent zones and an 85°C maximum; compare it separately with the SpacePi X4.
Documented comparison
What each product is actually positioned to solve
Mixed materials and high-temperature drying
Documented capability: Four spools; two independent chambers; up to 85°C
Decision limit: A displayed maximum is not proof that every loaded spool reaches the target uniformly.
Official SpacePi X4 specification ↗Affiliate link. We may earn a commission at no extra cost to you.
Check SpacePi X4 price at CrealityFour spools sharing one target at or below 70°C
Documented capability: Four spools; eight feed holes; up to 70°C; automatic humidity control
Decision limit: The single shared chamber is not documented as independently zoned.
Official SUNLU S4 specification ↗Affiliate link. We may earn a commission at no extra cost to you.
Check FilaDryer S4 at SUNLUThree checks before buying
Use the constraint that changes the answer
Does the exact spool require more than 70°C?
If yes, the S4 is below the requirement on paper. The X4 clears an 80°C cycle but still cannot satisfy a 100°C data sheet.
Will two materials dry at different settings?
Independent X4 chambers matter when the load needs different targets. They add little when all four spools share one validated cycle.
Do not convert a maximum into a test result.
Sensor placement, load, airflow, spool mass, ambient temperature, and calibration remain unmeasured here.
Decision path
Resolve the purchase in this order
- 01Read the exact filament data sheet.
Record its temperature, time, humidity target, and spool heat limit.
- 02Define the simultaneous load.
Count the spools and decide whether they genuinely require independent temperatures.
- 03Reject insufficient ceilings.
Do not lower a material requirement merely to make a dryer appear compatible.
Primary source trail
Official pages used for this comparison
Confirm the current regional product page, exact filament data sheet, spool heat limit, electrical requirements, safety instructions, availability, and warranty before purchasing.