iMac RAM Upgrade
iMac RAM UpgradeJohannesburg & Gauteng
Modern Safari, Lightroom, and 47 tabs of Slack running on 8GB? You can hear the iMac sighing from across the room. 16GB, 32GB, 64GB upgrades on every socketed Intel iMac — R1,600 per 8GB module, under an hour on rear-panel models. Free diagnostic, nationwide courier.
R1,600 per 8GB DDR4 · 27-inch: same-day · 21.5-inch: display removal required · 6-month warranty
iMac RAM upgrade compatibility
| Model | Max RAM | RAM type | Bus speed | Display removal needed? |
|---|---|---|---|---|
| iMac 27-inch — All models upgradeable via rear panel (no display removal) | ||||
| iMac 27-inch (Late 2013) | 32GB | DDR3 SO-DIMM | 1600MHz | No — rear panel Easy |
| iMac 27-inch (Late 2014) | 32GB | DDR3 SO-DIMM | 1600MHz | No — rear panel Easy |
| iMac 27-inch 5K (Mid 2015) | 32GB | DDR3 SO-DIMM | 1600MHz | No — rear panel Easy |
| iMac 27-inch 5K (Late 2015) | 64GB | DDR3 SO-DIMM | 1867MHz | No — rear panel Easy |
| iMac 27-inch 5K (2017) | 64GB | DDR4 SO-DIMM | 2400MHz | No — rear panel Easy |
| iMac 27-inch 5K (2019) | 128GB | DDR4 SO-DIMM | 2666MHz | No — rear panel Easy |
| iMac 27-inch 5K (2020) | 128GB | DDR4 SO-DIMM | 2666MHz | No — rear panel Easy |
| iMac 21.5-inch — upgrade status varies by year | ||||
| iMac 21.5-inch (Late 2012) | 16GB | DDR3 SO-DIMM | 1600MHz | Yes — display removal Possible |
| iMac 21.5-inch (Late 2013) | 16GB | DDR3 SO-DIMM | 1600MHz | Yes — display removal Possible |
| iMac 21.5-inch (Mid 2014) iMac14,4 — only model this year |
Not upgradeable | Soldered LPDDR3 | 1600MHz | Soldered — impossible |
| iMac 21.5-inch (Late 2015) iMac16,1 — non-4K |
Not upgradeable | Soldered LPDDR3 | 1867MHz | Soldered — impossible |
| iMac 21.5-inch 4K (Late 2015) iMac16,2 — 4K model |
Not upgradeable | Soldered LPDDR3 | 1867MHz | Soldered — impossible |
| iMac 21.5-inch (2017) iMac18,1 & iMac18,2 — all configs |
32GB | DDR4 SO-DIMM | 2133MHz | Yes — display removal Possible |
| iMac 21.5-inch 4K (2019) iMac19,2 — i3 runs at 2400MHz |
32GB | DDR4 SO-DIMM | 2666MHz* | Yes — display removal Possible |
| iMac 24-inch (Apple Silicon) — RAM not upgradeable | ||||
| iMac 24-inch M1 (2021) | Not upgradeable | Unified Memory (on-chip) | — | Integrated — impossible |
| iMac 24-inch M3 (2023) | Not upgradeable | Unified Memory (on-chip) | — | Integrated — impossible |
| iMac 24-inch M4 (2024) | Not upgradeable | Unified Memory (on-chip) | — | Integrated — impossible |
| iMac Pro (2017) — full-size 288-pin server ECC RAM · full logic board extraction required | ||||
| iMac Pro (2017) iMacPro1,1 · 4 slots · full-size 288-pin ECC DIMM — not SO-DIMMs · requires display removal + logic board extraction |
Up to 256GB | DDR4 2666MHz ECC RDIMM or LRDIMM (288-pin) | 2666MHz | Yes — display removal + full logic board extraction Specialist job |
* iMac 21.5-inch 4K 2019 with 3.6GHz Core i3 processor runs DDR4 2666MHz SO-DIMMs at 2400MHz. Core i5 and i7 configurations run at full 2666MHz.
iMac RAM upgrade pricing
Estimates only. Final price confirmed after checking your current configuration. Written quote before work begins.
| Service | Estimate |
|---|---|
| RAM — per 8GB DDR4 module Price per module. Configuration confirmed before ordering to ensure speed matching. |
R1,600 |
| 27-inch Intel iMac — 8GB → 16GB Add 2× 8GB to existing 8GB configuration. Rear panel only — no display removal. |
R3,200 |
| 27-inch Intel iMac — 8GB → 32GB Replace all sticks with 4× 8GB DDR4. Rear panel only — no display removal. |
R6,400 |
| 27-inch Intel iMac — upgrade to 64GB 4× 16GB DDR4. Maximum config on most 2015–2019 27-inch models. |
R12,800 |
| 21.5-inch Intel iMac — RAM upgrade (2013–2015) Requires full display removal. Labour + OEM adhesive strips included. |
From R3,200 + R800 labour |
| 21.5-inch iMac (2017, all models) — RAM upgrade Requires display removal. All 2017 21.5-inch models have SO-DIMM slots — upgradeable to 32GB by technician. |
From R3,200 + R800 labour |
| iMac Pro RAM upgrade — DDR4 2666MHz ECC RDIMM/LRDIMM Full-size 288-pin server RAM (not SO-DIMMs). Display removal + full logic board extraction required. Parts sourced to order — price confirmed on booking. |
Assessment + quote |
| Collection and return — Gauteng Door-to-door via Eliz Courier. Insured. |
R500 |
Is your iMac starved for memory?
Spinning beachball constantly
The most common sign of RAM pressure. macOS is waiting for memory to free up before responding.
Apps slow down with multiple windows
Each app needs RAM to stay active. When RAM runs out macOS starts swapping to the SSD — much slower.
Memory Pressure shows yellow or red
Open Activity Monitor → Memory tab. Yellow or red pressure means your system is struggling.
Swap Used is above zero
Any Swap Used value means your Mac is using the SSD as overflow RAM. A RAM upgrade eliminates this.
Parallels / Windows VM runs poorly
Virtual machines need dedicated RAM to run smoothly. 8GB shared between macOS and Windows is not enough.
Browser with 10+ tabs causes slowdowns
Modern browsers are memory-hungry. 32+ tabs on 8GB causes constant reloading and beachballing.
Maximum RAM, bus speed & SO-DIMM spec by model
⚠ iMac 21.5-inch RAM — which models can be upgraded?
- Late 2012 & Late 2013 (21.5-inch): Two SO-DIMM slots are present but require full display removal to access. Upgradeable to 16GB by a technician.
- Mid 2014 (21.5-inch, 1.4GHz — iMac14,4): RAM is permanently soldered. No upgrade is possible under any circumstances — not even with display removal.
- Late 2015 (all 21.5-inch — iMac16,1 / iMac16,2): RAM fully soldered. No upgrade possible at all.
- 2017 (all 21.5-inch — iMac18,1 & iMac18,2): SO-DIMM slots are present. Apple calls this "not user removable" but a technician can upgrade to 32GB with display removal.
- 2019 (21.5-inch 4K — iMac19,2): SO-DIMM slots present — upgradeable to 32GB DDR4 with display removal. Note: the i3 configuration (3.6GHz) runs 2666MHz sticks at 2400MHz. i5 and i7 models run at full 2666MHz.
- iMac Pro (2017 — iMacPro1,1): 4 physical RAM slots, upgradeable to 256GB. Uses full-size 288-pin DDR4 2666MHz ECC RDIMM or LRDIMM server RAM — not laptop SO-DIMMs. Do not mix RDIMM and LRDIMM. Requires display removal AND full logic board extraction (3–5 hours). Parts sourced to order from server RAM suppliers.
- To confirm your model: About This Mac → Model Identifier. iMac14,4 = Mid 2014 soldered. iMac16,x = 2015 soldered. iMac18,x = 2017 upgradeable by technician.
Installing mismatched RAM speeds forces the iMac to run all sticks at the lowest common denominator — negating the upgrade. We always match bus speed precisely to your model before ordering.
| Model | Max RAM | SO-DIMM type | Bus speed | Dual-channel? |
|---|---|---|---|---|
| iMac 27-inch (Late 2013) | 32GB | DDR3 SO-DIMM | 1600MHz | Yes — 2 pairs |
| iMac 27-inch (2014–2015) | 32GB | DDR3 SO-DIMM | 1600MHz | Yes — 2 pairs |
| iMac 27-inch (Late 2015) | 64GB | DDR3 SO-DIMM | 1867MHz | Yes — 2 pairs |
| iMac 27-inch (2017) | 64GB | DDR4 SO-DIMM | 2400MHz | Yes — 2 pairs |
| iMac 27-inch (2019) | 128GB | DDR4 SO-DIMM | 2666MHz | Yes — 2 pairs |
| iMac 21.5-inch (2013–2014) | 16GB | DDR3 SO-DIMM | 1600MHz | Yes — display removal required |
| iMac 21.5-inch (2015) | 16GB | DDR3 SO-DIMM | 1867MHz | Yes — display removal required |
| iMac 21.5-inch (2017–2019) | Not upgradeable | Soldered LPDDR4 | — | N/A |
| iMac 24-inch M1/M3/M4 | Not upgradeable | Unified Memory (on-chip) | — | N/A |
Dual-channel architecture & bus speed matching explained
- Dual-channel: Installing RAM in matched pairs (2×8GB or 4×8GB) doubles the memory bandwidth versus a single stick. Always install in pairs for maximum performance.
- Bus speed matching: If you mix 1600MHz and 1867MHz sticks, all sticks run at 1600MHz. We verify the exact spec of your existing modules before sourcing replacements.
- SO-DIMM form factor: All iMac RAM uses the small SO-DIMM format — not the full-size DIMM used in desktop PCs. Standard desktop RAM will not fit.
- DDR3 vs DDR4: These are not interchangeable. A DDR4 stick physically cannot seat in a DDR3 slot. We confirm your generation before ordering.
Which iMac do you have?
Jump to your exact model for model-specific pricing, parts, and known faults.
iMac 24-inch M-series
View M-series repairs →2017 XeoniMac Pro
View Pro repairs →2019 - 2020iMac 27-inch (late Intel)
View 27" late Intel repairs →2015 - 2017iMac 27-inch 5K
View 27" 5K repairs →2013 - 2014iMac 27-inch
View 27" early repairs →2017 - 2019iMac 21.5-inch 4K
View 21.5" 4K repairs →2013 - 2015iMac 21.5-inch
View 21.5" early repairs →iMac RAM upgrade process
Free diagnostic
We check Activity Monitor, confirm current RAM spec and configuration, and identify the maximum supported upgrade for your model.
Compatible modules sourced
Matched-pair DDR3 or DDR4 SO-DIMMs rated for your specific iMac model. Wrong speed pairing reduces performance even if it physically fits.
RAM installed
27-inch: rear panel opened in seconds, sticks installed, panel closed. 21.5-inch: display removed, RAM replaced, dust clean, display resealed.
macOS verified
We boot into About This Mac, confirm the new RAM total, run a memory test, and check Activity Monitor to confirm pressure has dropped.
Returned to you
27-inch upgrades ready same day. 21.5-inch upgrades take 3–4 hours. Collect or arrange delivery.
Three ways to get your iMac to us
Drop it off, arrange Gauteng collection, or ship from anywhere in South Africa. iMacs are heavy and the displays are fragile — we transport them properly.
Drop it off at the workshop
Walk in to our Silvamonte workshop any business day. Free parking, free diagnostic on the spot. Bring the original box if you still have it — otherwise we have appropriate transport packaging on hand.
11 Swemmer Rd, Silvamonte, Johannesburg
Mon-Fri 08:00-17:30 · Sat 08:00-14:00
Door-to-door via Eliz Courier
Eliz Courier & Messenger Services collects and returns your iMac across Joburg, Pretoria, Centurion, and the East Rand. R500 round-trip — slightly higher than our laptop rate because iMacs need specialist transport packaging and careful handling.
WhatsApp to book collection →Ship via The Courier Guy
Anywhere in South Africa — Cape Town, Durban, PE, Bloem, Polokwane. We arrange Courier Guy collection from your door with proper iMac packaging, repair, and return. Pricing depends on size; WhatsApp us with your model.
WhatsApp to arrange courier →Service areas across Gauteng
iAssist Repair serves the entire Gauteng province. Collection and delivery across Johannesburg and Pretoria (R500 for iMacs). If your area isn't listed, contact us.
Find Your Service Area
Start typing your suburb to filter the areas below
Johannesburg & Pretoria Service Areas
Click to expand service areas. Tap any suburb for local collection details & pricing.
Johannesburg Central & Parks Click to expand
Sandton & Surrounding Suburbs Click to expand
Randburg & Northcliff Click to expand
Fourways & Midrand Click to expand
Roodepoort & West Rand Click to expand
Johannesburg South & Alberton Click to expand
Bedfordview & Edenvale Click to expand
East Rand (Ekurhuleni) Click to expand
Centurion Click to expand
Pretoria Click to expand
Apple repair by province — nationwide courier
Outside Gauteng? We collect and return your iMac nationwide via secure courier.
iMac RAM upgrade — FAQ
How much does an iMac RAM upgrade cost?
iAssist charges R1,600 per 8GB DDR4 module. A 27-inch iMac upgrade from 8GB to 32GB uses four 8GB sticks at R6,400, or you can add just two sticks to bring an existing 8GB machine to 24GB. We will confirm the optimal configuration for your specific model before ordering.
Which iMac models support a RAM upgrade?
The iMac 27-inch from 2013 through 2020 (Intel) has user-accessible RAM via a panel on the rear — no display removal required and upgrades are available up to 64GB (2013–2014 DDR3) or 128GB (2015–2020 DDR4). The iMac 21.5-inch from 2013–2015 can be upgraded but requires full display removal. The iMac 21.5-inch from 2017 onwards and all Apple Silicon iMacs (M1, M3, M4) have RAM integrated into the chip — no upgrade is possible.
Does the iMac 27-inch RAM upgrade require opening the display?
No — the 27-inch Intel iMac has a dedicated RAM access panel on the rear of the machine that opens in seconds with no tools. Sticks slide in, panel closes. No display removal, no adhesive, no risk to the screen. Most 27-inch upgrades are complete in under an hour.
How much RAM does my iMac actually need?
For general use, web browsing, and email 8GB is workable but 16GB makes a noticeable difference. For Lightroom, Final Cut Pro, Parallels, or keeping 20+ browser tabs open, 32GB is the sweet spot. If you use virtual machines or heavy video work, 64GB or more makes sense on the 27-inch models.
How do I know if I need more RAM?
Open Activity Monitor, click the Memory tab, and look at Memory Pressure at the bottom. Yellow or red pressure means your Mac is struggling. Also check Swap Used — if this is anything other than zero your Mac is using the much slower SSD as overflow memory and more RAM will make an immediate difference.
Can I add RAM to my existing sticks or must I replace all of them?
On the 27-inch iMac you can add matched pairs to empty slots without replacing existing sticks, provided the new modules match the speed of the existing ones. We check your current configuration before ordering to ensure compatibility and optimal performance.
How long does an iMac RAM upgrade take?
27-inch iMac RAM upgrades are completed same day — often within an hour if you drop off in the morning. 21.5-inch upgrades that require display removal take 3 to 4 hours due to the additional work involved.
Do you offer collection for iMac RAM upgrades?
Yes — R500 door-to-door collection and return across Gauteng. WhatsApp us on 078 742 4769 to arrange pickup from your door.
Visit Our Repair Centre
iAssist Repair– Johannesburg
Shop 4, Silvercrest Centre
11 Swemmer Rd, Silvamonte, Johannesburg
Prefer convenience?
We offer collection & delivery across Johannesburg.
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