diff --git a/persistent-memory.d/2026-09-01-ada-inference-server-r750xa.md b/persistent-memory.d/2026-09-01-ada-inference-server-r750xa.md
index 3334422..d9810c8 100644
--- a/persistent-memory.d/2026-09-01-ada-inference-server-r750xa.md
+++ b/persistent-memory.d/2026-09-01-ada-inference-server-r750xa.md
@@ -26,12 +26,27 @@ separate machine → [[2026-09-01-pfi-gx10-onboarding]].
 | **GPU cables** | `470-AEVS` 4-GPU kit: `4RW1P` `W4K7M` `XC48N` `6C77X` | **not listed** |
 | **Riser cables** | signal `CP67W` `CXYF8` `H4D7D` `N61TK`; power `HXJDR` `W1P56`; pad `C2JNP` | **not listed** |
 | **Fans** | 6× `FD00R` **Very High Performance** | **not listed** |
+| **CPU** | **2× Xeon Platinum 8362** 32C/64T, 265 W, **DDR4-3200** (`338-CCUS`/`W51V5`) | **2× Xeon Silver 4314** 16C/32T, 135 W, **DDR4-2666** |
 | **Controller** | PERC H345 | **HBA355i — an UPGRADE for us** |
 | **Drives** | 2× 480 GB | 2× 1.92 TB |
 
 ⚠ **"Not listed on the invoice" is not proof of removal.** Operator will pull an iDRAC
 inventory to settle it. Diff that against the CSV rather than the invoice.
 
+⚠ **The CPU row was MISSING from this table until 2026-09-01** — the Silver 4314s were
+recorded under "As bought" but never diffed against the factory CSV, so the swap went
+unremarked. It has two live consequences:
+
+- **Memory speed:** Silver 4314 caps at **DDR4-2666**; Platinum 8362 ran 3200. The box
+  **cannot use the 3200 rating** of the factory-spec `M04W6` parts on the buy list. Any
+  DDR4-2666 RDIMM performs identically in this chassis as configured.
+  ⚠ Verify the 2666 figure on Intel ARK before spending on it.
+- **Power, in our favour:** 270 W of CPU instead of 530 W. The ~1,020 W sustained figure
+  below already assumes the Silvers and is correct as written.
+
+Cores went 64C/128T → 32C/64T. For an inference/render box that is largely irrelevant; noted
+so nobody re-derives it as a surprise later.
+
 ## The GPU power chain — resolved, and my first answer was wrong
 
 **RTX 6000 Ada: 300 W, ACTIVE cooling, one 16-pin 12VHPWR (CEM5) connector** (nvidia.com).
@@ -116,11 +131,31 @@ circuit this lands on before racking, not after.**
 
 ## Buy list
 
-**Certain:**
+⚠ **THE RAM LINE MAY BE FREE — operator has 2x Dell R640 with 768 GB each (2026-09-01).**
+Both are DDR4 **RDIMM** platforms (factory `M04W6` = `DIMM,16GB,3200,2RX8,8G,DDR4,**R**`), so
+the part class is the same 288-pin 1.2 V DDR4 RDIMM and Dell does not vendor-lock DIMMs.
+Three things decide it, in order:
+
+1. **RDIMM vs LRDIMM.** 768 GB in an R640's 24 slots is almost certainly **24x 32 GB 2Rx4
+   RDIMM** — the safe case, drops straight in. If it is instead **12x 64 GB LRDIMM**, verify
+   Ice Lake-SP / R750xa LRDIMM support first; do NOT assume it.
+2. **Speed is a non-issue as configured.** R640 DIMMs are 2666 or 2933; the Silver 4314s cap
+   the box at **2666** regardless (see the CPU note above), so 2666 parts lose **nothing**
+   against the 3200-rated `M04W6`. ⚠ It WOULD become a cap if the Platinum 8362s were ever
+   restored — the factory CPUs ran 3200.
+3. **Slot arithmetic.** R750xa has **16** slots (8 channels/socket, 1 DPC); R640 has 24.
+   **16x 32 GB = 512 GB — double the factory 256 GB spec**, and it kills the 8x `M04W6` line
+   entirely. Cleanest harvest: **strip ONE R640 of all 24, use 16, keep 8 as spares**, leaving
+   the second R640 whole — rather than half-emptying both into unbalanced populations.
+
+⚠ **Confirm the actual DIMM part numbers from iDRAC or the DIMM labels before ordering
+anything.** And confirm the R640s are spares, not in service.
+
+**Certain (pending the R640 harvest above, which may delete the RAM line):**
 
 | item | part | qty |
 |---|---|---|
-| RDIMM 16 GB 3200 2Rx8 | **`M04W6`** | **8** → restores 256 GB, all 16 slots, all 8 channels/socket |
+| RDIMM 16 GB 3200 2Rx8 | **`M04W6`** | **8** → restores 256 GB. **Buy only if the R640 harvest fails**; 16x 32 GB from an R640 gives 512 GB free |
 | NVIDIA 12VHPWR adapter | **`930-00030-1546-000`** | **2** |
 | 2 TB SATA SSD (any; match/exceed the MX500s) | — | **2** → pool ~3.57 TiB at ~41%; without it the migration lands at ~84%. Pair the two NEW drives together, not one-each with a 1.92 |
 
@@ -128,7 +163,8 @@ circuit this lands on before racking, not after.**
 `XC48N`, `6C77X`, `CP67W`, `CXYF8`, `H4D7D`, `N61TK`, `HXJDR`, `W1P56`, `C2JNP`,
 `FD00R` ×6.
 
-**Spend order:** RAM → **2 SATA SSDs (now certain, capacity-driven)** → check PCIe slots →
+**Spend order:** **check the R640 DIMM part numbers FIRST (may zero the RAM line and double
+the RAM)** → RAM only if that fails → **SATA SSDs (certain, capacity-driven)** → check PCIe slots →
 only then consider filling the remaining bays. (The original order deprioritised drives on a
 *throughput* argument, which still holds; the drives are now on the certain list for
 **capacity**, which is a different axis.)